Trigonometry (11th Edition)
11th Edition
ISBN: 9780134217437
Author: Margaret L. Lial, John Hornsby, David I. Schneider, Callie Daniels
Publisher: PEARSON
expand_more
expand_more
format_list_bulleted
Videos
Textbook Question
Chapter 4.3, Problem 17E
Graph each
Expert Solution & Answer
Learn your wayIncludes step-by-step video
schedule05:43
Students have asked these similar questions
pls exact values
Find the polar representations of a point which has -л<О≤л and is symmetrical to
the given point with respect to the origin.
(√2.- 1/1)
π
4
Find the area of a triangle formed by the pole and the two points with polar
coordinates.
π
A 5,
-
B(10, 2π)
Chapter 4 Solutions
Trigonometry (11th Edition)
Ch. 4.1 - CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.1 -
CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.1 - CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.1 - CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.1 -
5. The least positive number x for which cos x =...Ch. 4.1 - CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.1 - Concept Check Match each function with its graph...Ch. 4.1 - Concept Check Match each function with its graph...Ch. 4.1 -
Concept Check Match each function with its graph...Ch. 4.1 - Concept Check Match each function with its graph...
Ch. 4.1 - Concept Check Match each function with its graph...Ch. 4.1 - Concept Check Match each function with its graph...Ch. 4.1 -
Graph each function over the interval [ –2π, 2π]....Ch. 4.1 - Graph each function over the interval [ 2, 2]....Ch. 4.1 - Graph each function over the interval [2, 2]. Give...Ch. 4.1 -
Graph each function over the interval [–2π, 2π]....Ch. 4.1 - Graph each function over the interval [2,2]. Give...Ch. 4.1 -
Graph each function over the interval [–2π,2π]....Ch. 4.1 -
Graph each function over the interval [–2 π,2π]....Ch. 4.1 - Graph each function over the interval [–2π,2π]....Ch. 4.1 - Graph each function over the interval [2,2 ]. Give...Ch. 4.1 - Prob. 22ECh. 4.1 - Graph each function over a two-period interval....Ch. 4.1 -
Graph each function over a two-period interval....Ch. 4.1 -
Graph each function over a two-period interval....Ch. 4.1 - Graph each function over a two-period interval....Ch. 4.1 - Graph each function over a two-period interval....Ch. 4.1 - Graph each function over a two-period interval....Ch. 4.1 - Graph each function over a two-period interval....Ch. 4.1 -
Graph each function over a two-period interval....Ch. 4.1 - Graph each function over a two-period interval....Ch. 4.1 -
Graph each function over a two-period interval....Ch. 4.1 - Graph each function over a two-period interval....Ch. 4.1 -
Graph each function over a two-period interval....Ch. 4.1 -
Graph each function over a two-period interval....Ch. 4.1 -
Graph each function over a two-period interval....Ch. 4.1 -
Graph each function over a two-period interval....Ch. 4.1 -
Graph each function over a two-period interval....Ch. 4.1 - Graph each function over a two-period interval....Ch. 4.1 - Graph each function over a two-period interval....Ch. 4.1 - Connecting Graphs with Equations Determine an...Ch. 4.1 - Connecting Graphs with Equations Determine an...Ch. 4.1 - Connecting Graphs with Equations Determine an...Ch. 4.1 - Connecting Graphs with Equations Determine an...Ch. 4.1 - Connecting Graphs with Equations Determine an...Ch. 4.1 - Connecting Graphs with Equations Determine an...Ch. 4.1 - Average Annual Temperature Scientists believe that...Ch. 4.1 - Blood Pressure Variation The graph gives the...Ch. 4.1 - Prob. 49ECh. 4.1 - Prob. 50ECh. 4.1 - Prob. 51ECh. 4.1 - Prob. 52ECh. 4.1 - Prob. 53ECh. 4.1 - Activity of a Nocturnal Animal Many activities of...Ch. 4.1 -
55. Atmospheric Carbon Dioxide At Mauna Loa....Ch. 4.1 - Atmospheric Carbon Dioxide Refer to Exercise 55....Ch. 4.1 -
57. Average Daily Temperature The temperature in...Ch. 4.1 - 58. Fluctuation in the Solar Constant The solar...Ch. 4.1 -
Musical Sound Waves Pure sounds produce single...Ch. 4.1 - Musical Sound Waves Pure sounds produce single...Ch. 4.1 - Prob. 61ECh. 4.1 - Prob. 62ECh. 4.1 - Prob. 63ECh. 4.1 - Prob. 64ECh. 4.1 - Prob. 65ECh. 4.1 - Prob. 66ECh. 4.2 - CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.2 - CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.2 - CONCEPT PREVIEW Fill in the blanks to correctly...Ch. 4.2 - CONCEPT PREVIEW Fill in the blanks to correctly...Ch. 4.2 -
CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.2 - CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.2 -
CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.2 - CONCEPT PREVIEW Fill in the blanks to correctly...Ch. 4.2 - Concept Check Match each function with its graph...Ch. 4.2 - Concept Check Match each function with its graph...Ch. 4.2 - Concept Check Match each function w ith its graph...Ch. 4.2 - Concept Check Match each function w ith its graph...Ch. 4.2 - Concept Check Match each function with its graph...Ch. 4.2 - Concept Check Match each function with its graph...Ch. 4.2 - Concept Check Match each function with its graph...Ch. 4.2 - Concept Check Match each function with its graph...Ch. 4.2 - The graphs of y = sin x + 1 and y = sin(x + 1) are...Ch. 4.2 - Concept Check Refer to Exercise 17. Which one of...Ch. 4.2 -
Concept Check Match each function in Column I...Ch. 4.2 - Concept Check Match each function in Column I with...Ch. 4.2 -
Concept Check Match each function in Column I...Ch. 4.2 - Concept Check Match each function in Column I with...Ch. 4.2 - Concept Check Fill in each blank with the word...Ch. 4.2 - Prob. 24ECh. 4.2 - Connecting Graphs with equations Each function...Ch. 4.2 - Connecting Graphs with Equations Each function...Ch. 4.2 -
Connecting Graphs with Equations Each function...Ch. 4.2 - Prob. 28ECh. 4.2 -
Find the amplitude, the period, any vertical...Ch. 4.2 -
Find the amplitude, the period, any vertical...Ch. 4.2 -
Find the amplitude, the period, any vertical...Ch. 4.2 -
Find the amplitude, the period, any vertical...Ch. 4.2 - Find the amplitude, the period, any vertical...Ch. 4.2 -
Find the amplitude, the period, any vertical...Ch. 4.2 - Find the amplitude, the period, any vertical...Ch. 4.2 - Find the amplitude, the period, any vertical...Ch. 4.2 - Graph each function over a two-period interval....Ch. 4.2 - Graph each function over a two-period interval....Ch. 4.2 - Graph each function over a two-period interval....Ch. 4.2 - Graph each function over a two-period interval....Ch. 4.2 -
Graph each function over a two-period interval....Ch. 4.2 - Graph each function over a two-period interval....Ch. 4.2 -
Graph each function over a one-period interval....Ch. 4.2 -
Graph each function over a one-period interval....Ch. 4.2 - Graph each function over a one-period interval....Ch. 4.2 - Graph each function over a one-period interval....Ch. 4.2 - Graph each function over a one-period interval....Ch. 4.2 -
Graph each function over a one-period interval....Ch. 4.2 - Graph each function over a two-period interval....Ch. 4.2 - Graph each function over a two-period interval....Ch. 4.2 -
Graph each function over a two-period interval....Ch. 4.2 -
Graph each function over a two-period interval....Ch. 4.2 - Graph each function over a two-period interval....Ch. 4.2 -
Graph each function over a two-period interval....Ch. 4.2 -
Graph each function over a two-period interval....Ch. 4.2 - Graph each function over a two-period interval....Ch. 4.2 -
Graph each function over a two-period interval....Ch. 4.2 - Graph each function over a one-period interval....Ch. 4.2 -
Graph each function over a one-period interval....Ch. 4.2 - Prob. 60ECh. 4.2 - Average Monthly Temperature The average monthly...Ch. 4.2 - Prob. 62ECh. 4.2 - Prob. 63ECh. 4.2 - Prob. 64ECh. 4.2 - Prob. 65ECh. 4.2 - Prob. 66ECh. 4.2 - Prob. 1QCh. 4.2 - Graph each function over a two-period interval....Ch. 4.2 - Prob. 3QCh. 4.2 - Prob. 4QCh. 4.2 - Prob. 5QCh. 4.2 - Graph each function over a two-period interval....Ch. 4.2 - Prob. 7QCh. 4.2 - Prob. 8QCh. 4.2 - Prob. 9QCh. 4.2 - Prob. 10QCh. 4.2 - Prob. 11QCh. 4.2 - Prob. 12QCh. 4.3 - 1. The least positive value x for which tan x = 0...Ch. 4.3 - The least positive value x for which cot x = 0 is...Ch. 4.3 - Concept Check Fill in each blank with the word...Ch. 4.3 - Concept Check Fill in each blank with the word...Ch. 4.3 - The negative value k with the greatest value for...Ch. 4.3 - CONCEPT PREVIEW Fill in the blank(s) to correctly...Ch. 4.3 - Concept Check Match each function with its graph...Ch. 4.3 - Concept Check Match each function with its graph...Ch. 4.3 -
Concept Check Match each function with its...Ch. 4.3 - Concept Check Match each function with its graph...Ch. 4.3 - Concept CheckMatch each function with its graph...Ch. 4.3 - Concept Check Match each function with its graph...Ch. 4.3 - Graph each function over a one-period interval....Ch. 4.3 -
Graph each function over a one-period interval....Ch. 4.3 - Graph each function over a one-period interval....Ch. 4.3 - Graph each function over a one-period interval....Ch. 4.3 - Graph each function over a one-period interval....Ch. 4.3 - Graph each function over a one-period interval....Ch. 4.3 - Graph each function over a one-period interval....Ch. 4.3 - Graph each function over a one-period interval....Ch. 4.3 -
Graph each function over a one-period...Ch. 4.3 - Graph each function over a one-period interval....Ch. 4.3 - Graph each function over a one-period interval....Ch. 4.3 -
Graph each function over a one-period interval....Ch. 4.3 - Graph each function over a two-period interval....Ch. 4.3 -
Graph each function over a two-period interval....Ch. 4.3 -
Graph each function over a two-period...Ch. 4.3 -
Graph each function over a two-period...Ch. 4.3 - Graph each function over a two-period interval....Ch. 4.3 - Graph each function over a two-period interval....Ch. 4.3 - Prob. 31ECh. 4.3 - Graph each function over a two-period interval....Ch. 4.3 - Graph each function over a two-period interval....Ch. 4.3 - Prob. 34ECh. 4.3 - Graph each function over a two-period interval....Ch. 4.3 - Prob. 36ECh. 4.3 - Graph each function over a two-period interval....Ch. 4.3 - Prob. 38ECh. 4.3 - Prob. 39ECh. 4.3 - Prob. 40ECh. 4.3 - Prob. 41ECh. 4.3 - Prob. 42ECh. 4.3 - Prob. 43ECh. 4.3 - Prob. 44ECh. 4.3 - Concept Check Decide whether each statement is...Ch. 4.3 - Concept CheckDecide whether each statement is true...Ch. 4.3 -
Concept Check Decide whether each statement is...Ch. 4.3 - Prob. 48ECh. 4.3 - Concept Check If c is any number, then how many...Ch. 4.3 - Prob. 50ECh. 4.3 - 51. Show that tan(–x) = –tan x by writing tan(–x)...Ch. 4.3 - 52. Show that cot (–x) = –cot x by writing cot...Ch. 4.3 - Prob. 53ECh. 4.3 - Prob. 54ECh. 4.3 - Prob. 55ECh. 4.3 - Prob. 56ECh. 4.3 - Prob. 57ECh. 4.3 - Prob. 58ECh. 4.3 - Prob. 59ECh. 4.3 - Prob. 60ECh. 4.3 - Prob. 61ECh. 4.3 - Prob. 62ECh. 4.4 - CONCEPT PREVIEW Match each description in Column I...Ch. 4.4 -
CONCEPT PREVIEW Match each description in...Ch. 4.4 -
CONCEPT PREVIEW Match each description in Column...Ch. 4.4 -
CONCEPT PREVIEW Match each description in Column...Ch. 4.4 -
CONCEPT PREVIEW Match each description in Column...Ch. 4.4 -
CONCEPT PREVIEW Match each description in Column...Ch. 4.4 - Concept Check Match each function with its graph...Ch. 4.4 - Concept Check Match each function with its graph...Ch. 4.4 - Concept Check Match each function with its graph...Ch. 4.4 - Concept Check Match each function with its graph...Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 -
Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Graph each function over a one-period interval....Ch. 4.4 - Connecting Graphs with EquationsDetermine an...Ch. 4.4 - Connecting Graphs with Equations Determine an...Ch. 4.4 - Connecting Graphs with Equations Determine an...Ch. 4.4 - Connecting Graphs with Equations Determine an...Ch. 4.4 - Connecting Graphs with Equations Determine an...Ch. 4.4 - Prob. 30ECh. 4.4 - Concept CheckDecide whether each statement is true...Ch. 4.4 - Concept Check Decide whether each statement is...Ch. 4.4 - Concept CheckDecide whether each statement is true...Ch. 4.4 - Prob. 34ECh. 4.4 - 35. Concept Check If c is any number such that -1...Ch. 4.4 - Prob. 36ECh. 4.4 - 37. Show that sec (–x) = sec x by writing sec (–x)...Ch. 4.4 - Prob. 38ECh. 4.4 - Prob. 39ECh. 4.4 - (Modeling) Distance of a Rotating Beacon The...Ch. 4.4 - Prob. 41ECh. 4.4 - Prob. 42ECh. 4.4 - Prob. 43ECh. 4.4 - Prob. 44ECh. 4.4 - Prob. 45ECh. 4.4 - Prob. 46ECh. 4.4 - Prob. 1SECh. 4.4 - Prob. 2SECh. 4.4 - These summary exercises provide practice with the...Ch. 4.4 - Prob. 4SECh. 4.4 - Prob. 5SECh. 4.4 - Prob. 6SECh. 4.4 - Prob. 7SECh. 4.4 -
Graph each function over a two-period...Ch. 4.4 - Prob. 9SECh. 4.4 - Graph each function over a two-period...Ch. 4.5 - CONCEPT PREVIEW Refer to the equations in the...Ch. 4.5 - Prob. 2ECh. 4.5 - CONCEPT PREVIEW Refer to the equations in the...Ch. 4.5 - Prob. 4ECh. 4.5 - Prob. 5ECh. 4.5 - Prob. 6ECh. 4.5 - Spring Motion An object is attached to a coiled...Ch. 4.5 - Spring Motion Repeat Exercise 7, but assume that...Ch. 4.5 - 9. Voltage of an Electrical Circuit The voltage E...Ch. 4.5 - Prob. 10ECh. 4.5 - Particle Movement Write the equation and then...Ch. 4.5 - Prob. 12ECh. 4.5 -
13. Pendulum Motion What are the period P and...Ch. 4.5 - Prob. 14ECh. 4.5 - Spring Motion The formula for the up and down...Ch. 4.5 - Spring Motion (See Exercise 15.) A spring with...Ch. 4.5 - Spring Motion The position of a weight attached to...Ch. 4.5 - Spring Motion The position of a weight attached to...Ch. 4.5 - Spring Motion A weight attached to a spring is...Ch. 4.5 -
20. Spring Motion A weight attached to a spring...Ch. 4.5 -
(Modeling) Springs A weight on a spring has...Ch. 4.5 - Prob. 22ECh. 4.5 -
(Modeling) Springs A weight on a spring has...Ch. 4.5 -
(Modeling) Springs A weight on a spring has...Ch. 4.5 - Prob. 25ECh. 4.5 - Prob. 26ECh. 4.5 - Prob. 27ECh. 4.5 - Prob. 28ECh. 4.5 -
(Modeling) Spring Motion Consider the spring in...Ch. 4.5 - Prob. 30ECh. 4.5 - Prob. 31ECh. 4.5 - (Modeling) Spring Motion Consider the spring in...Ch. 4.5 - Prob. 33ECh. 4.5 - Prob. 34ECh. 4 - Concept Check Which one of the following...Ch. 4 - Prob. 2RECh. 4 - Prob. 3RECh. 4 - Prob. 4RECh. 4 - Prob. 5RECh. 4 - Prob. 6RECh. 4 - Prob. 7RECh. 4 - Prob. 8RECh. 4 -
For each function, give the amplitude, period,...Ch. 4 - Prob. 10RECh. 4 - Prob. 11RECh. 4 - Prob. 12RECh. 4 - Prob. 13RECh. 4 -
For each function, give the amplitude, period,...Ch. 4 - Prob. 15RECh. 4 - Prob. 16RECh. 4 - Prob. 17RECh. 4 - Prob. 18RECh. 4 - Prob. 19RECh. 4 - Prob. 20RECh. 4 - Prob. 21RECh. 4 - Prob. 22RECh. 4 - Prob. 23RECh. 4 - Prob. 24RECh. 4 - Prob. 25RECh. 4 - Prob. 26RECh. 4 - Prob. 27RECh. 4 - Prob. 28RECh. 4 - Prob. 29RECh. 4 - Prob. 30RECh. 4 - Prob. 31RECh. 4 - Prob. 32RECh. 4 - Graph each function over a one-period...Ch. 4 -
Graph each function over a one-period...Ch. 4 -
Graph each function over a one-period...Ch. 4 - Prob. 36RECh. 4 -
Graph each function over a one-period...Ch. 4 - Prob. 38RECh. 4 - Prob. 39RECh. 4 - Prob. 40RECh. 4 - Prob. 41RECh. 4 - Prob. 42RECh. 4 - (Modeling) Monthly Temperatures A set of...Ch. 4 - Prob. 44RECh. 4 - Prob. 45RECh. 4 - Prob. 46RECh. 4 - Prob. 47RECh. 4 - Prob. 48RECh. 4 - Prob. 49RECh. 4 - Prob. 50RECh. 4 - Prob. 51RECh. 4 - Prob. 52RECh. 4 - Prob. 53RECh. 4 - Prob. 54RECh. 4 - Prob. 55RECh. 4 - Prob. 56RECh. 4 - Prob. 57RECh. 4 - Prob. 58RECh. 4 - Prob. 1TCh. 4 - Prob. 2TCh. 4 - Prob. 3TCh. 4 - Prob. 4TCh. 4 - Prob. 5TCh. 4 - Prob. 6TCh. 4 - Prob. 7TCh. 4 - Prob. 8TCh. 4 - Prob. 9TCh. 4 - Prob. 10TCh. 4 - Prob. 11TCh. 4 - Prob. 12TCh. 4 - Average Monthly Temperature The average monthly...Ch. 4 -
14. Spring Motion The position of a weight...Ch. 4 - Prob. 15T
Additional Math Textbook Solutions
Find more solutions based on key concepts
Limits of sequences Find the limit of the following sequences or determine that the limit does not exist. 9. {n...
Calculus: Early Transcendentals (2nd Edition)
The blank in the statement “ 9pt≈ L ”.
Pre-Algebra Student Edition
The null hypothesis, alternative hypothesis, test statistic, P-value and state the conclusion. To test: Whether...
Elementary Statistics
Find how many SDs above the mean price would be predicted to cost.
Intro Stats, Books a la Carte Edition (5th Edition)
Heights and z-Scores The dotplot shows heights of college women; the mean is 64 inches (5 feet 4 inches), and t...
Introductory Statistics
If n is a counting number, bn, read______, indicates that there are n factors of b. The number b is called the_...
Algebra and Trigonometry (6th Edition)
Knowledge Booster
Learn more about
Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, trigonometry and related others by exploring similar questions and additional content below.Similar questions
- Plot each point given its polar coordinates. Then, give another pair of polar coordinates for the same point with the opposite radius and angle 0 ≤ 0 < 2π (or 0 ≤ 0 < 360°). (-6, 120°)arrow_forwardFind two additional polar representations of the given point such that one has the same sign as r but the opposite sign of 0, and the other has the opposite sign of r but the same sign as 0. 3, - π 6arrow_forwarde consider the problem -((1+x)))= 0 XE U(0) = 0, 'U(1)=\@Sind the analytical sol and he Find the Variational form and find Matrix A and b? consider the Variational form a (u,v)-(SV) where acu,v) = vdx prove that YVE H. (0,1),i=1, 2, \\-\ a(vi)=-v(x-1)+2V(xi)-(X;+1)] Where Vn is usual basis of hat functions. Consider the Problem Au=f and u= du=0 0 a with bilinear formalu,v) = SAU. AV r Prove that alu, v). V-ellPitic. and aluv) is continuous..arrow_forward
- The resistance, R, of a conductor is directly proportional to its length, 7. If the resistance. of 3.80 km of a certain transmission line is 121 ohms, find the resistance of 74.9 km of that line. Round your answer to 3 significant digits. Ωarrow_forwardThe number of widgets that a manufacturing plant can produce varies jointly as the number of workers and the time that they have worked. Find the constant of proportionality k to 2 decimal places if 455 workers work 6 hours and can produce 11493.3 widgets. k = How many widgets (to the nearest tenth) can be produced by 490 workers in 37 hours? Widgets =arrow_forward### Based on the figure below, find an equation in which you can determine x as a function of only z, y, a, and barrow_forward
- Z x ·b-arrow_forwardNo A.i Solve pleasearrow_forwardSketch the graph of a function y − f(2) such that all of the following statements are true: - • lim_ f(x) — −2 1+0+ lim f(x)-1 1+0 • f(0) - -1 ⚫lim f(x) - co 2 lim f(x) - 1+2+ --∞ H NW 2 3 6 5 4 -6 - 5 -4 -3 -2 -1 1 2 3 4 -1 -2 -3 -4 -5 -6 20 5 6 7arrow_forward
arrow_back_ios
SEE MORE QUESTIONS
arrow_forward_ios
Recommended textbooks for you
Trigonometry (MindTap Course List)TrigonometryISBN:9781337278461Author:Ron LarsonPublisher:Cengage Learning
College Algebra (MindTap Course List)AlgebraISBN:9781305652231Author:R. David Gustafson, Jeff HughesPublisher:Cengage Learning
Mathematics For Machine TechnologyAdvanced MathISBN:9781337798310Author:Peterson, John.Publisher:Cengage Learning,
Algebra & Trigonometry with Analytic GeometryAlgebraISBN:9781133382119Author:SwokowskiPublisher:Cengage
College AlgebraAlgebraISBN:9781305115545Author:James Stewart, Lothar Redlin, Saleem WatsonPublisher:Cengage Learning
Trigonometry (MindTap Course List)
Trigonometry
ISBN:9781337278461
Author:Ron Larson
Publisher:Cengage Learning
College Algebra (MindTap Course List)
Algebra
ISBN:9781305652231
Author:R. David Gustafson, Jeff Hughes
Publisher:Cengage Learning
Mathematics For Machine Technology
Advanced Math
ISBN:9781337798310
Author:Peterson, John.
Publisher:Cengage Learning,
Algebra & Trigonometry with Analytic Geometry
Algebra
ISBN:9781133382119
Author:Swokowski
Publisher:Cengage
College Algebra
Algebra
ISBN:9781305115545
Author:James Stewart, Lothar Redlin, Saleem Watson
Publisher:Cengage Learning
Sine, Cosine and Tangent graphs explained + how to sketch | Math Hacks; Author: Math Hacks;https://www.youtube.com/watch?v=z9mqGopdUQk;License: Standard YouTube License, CC-BY