Differential Equations: Computing and Modeling (5th Edition), Edwards, Penney & Calvis
5th Edition
ISBN: 9780321816252
Author: C. Henry Edwards, David E. Penney, David Calvis
Publisher: PEARSON
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Chapter 3.1, Problem 14P
Program Plan Intro
Program Description:Purpose of problem is to verify that
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A ladder 25 feet long is leaning against the wall of a building. Initially, the foot of the ladder is 7 feet from the wall. The foot of the ladder begins to slide at a rate of 2 ft/sec, causing the top of the ladder to slide down the wall. The location of the foot of the ladder, its x coordinate, at time t seconds is given by
x(t)=7+2t.
wall
y(1)
25 ft. ladder
x(1)
ground
(a) Find the formula for the location of the top of the ladder, the y coordinate, as a function of time t. The formula for y(t)= √ 25² - (7+2t)²
(b) The domain of t values for y(t) ranges from 0
(c) Calculate the average velocity of the top of the ladder on each of these time intervals (correct to three decimal places):
. (Put your cursor in the box, click and a palette will come up to help you enter your symbolic answer.)
time interval
ave velocity
[0,2]
-0.766
[6,8]
-3.225
time interval
ave velocity
-1.224
-9.798
[2,4]
[8,9]
(d) Find a time interval [a,9] so that the average velocity of the top of the ladder on this…
Total marks 15
3.
(i)
Let FRN Rm be a mapping and x = RN is a given
point. Which of the following statements are true? Construct counterex-
amples for any that are false.
(a)
If F is continuous at x then F is differentiable at x.
(b)
If F is differentiable at x then F is continuous at x.
If F is differentiable at x then F has all 1st order partial
(c)
derivatives at x.
(d) If all 1st order partial derivatives of F exist and are con-
tinuous on RN then F is differentiable at x.
[5 Marks]
(ii) Let mappings
F= (F1, F2) R³ → R² and
G=(G1, G2) R² → R²
:
be defined by
F₁ (x1, x2, x3) = x1 + x²,
G1(1, 2) = 31,
F2(x1, x2, x3) = x² + x3,
G2(1, 2)=sin(1+ y2).
By using the chain rule, calculate the Jacobian matrix of the mapping
GoF R3 R²,
i.e., JGoF(x1, x2, x3). What is JGOF(0, 0, 0)?
(iii)
[7 Marks]
Give reasons why the mapping Go F is differentiable at
(0, 0, 0) R³ and determine the derivative matrix D(GF)(0, 0, 0).
[3 Marks]
5.
(i)
Let f R2 R be defined by
f(x1, x2) = x² - 4x1x2 + 2x3.
Find all local minima of f on R².
(ii)
[10 Marks]
Give an example of a function f: R2 R which is not bounded
above and has exactly one critical point, which is a minimum. Justify briefly
Total marks 15
your answer.
[5 Marks]
Chapter 3 Solutions
Differential Equations: Computing and Modeling (5th Edition), Edwards, Penney & Calvis
Ch. 3.1 - In Problems 1 through 16, a homogeneous...Ch. 3.1 - Prob. 2PCh. 3.1 - Prob. 3PCh. 3.1 - Prob. 4PCh. 3.1 - Prob. 5PCh. 3.1 - Prob. 6PCh. 3.1 - Prob. 7PCh. 3.1 - Prob. 8PCh. 3.1 - Prob. 9PCh. 3.1 - Prob. 10P
Ch. 3.1 - Prob. 11PCh. 3.1 - Prob. 12PCh. 3.1 - Prob. 13PCh. 3.1 - Prob. 14PCh. 3.1 - Prob. 15PCh. 3.1 - Prob. 16PCh. 3.1 - Prob. 17PCh. 3.1 - Prob. 18PCh. 3.1 - Prob. 19PCh. 3.1 - Prob. 20PCh. 3.1 - Prob. 21PCh. 3.1 - Prob. 22PCh. 3.1 - Prob. 23PCh. 3.1 - Prob. 24PCh. 3.1 - Prob. 25PCh. 3.1 - Prob. 26PCh. 3.1 - Prob. 27PCh. 3.1 - Prob. 28PCh. 3.1 - Prob. 29PCh. 3.1 - Prob. 30PCh. 3.1 - Prob. 31PCh. 3.1 - Let y1andy2 be two solutions of...Ch. 3.1 - Prob. 33PCh. 3.1 - Prob. 34PCh. 3.1 - Prob. 35PCh. 3.1 - Prob. 36PCh. 3.1 - Prob. 37PCh. 3.1 - Prob. 38PCh. 3.1 - Prob. 39PCh. 3.1 - Prob. 40PCh. 3.1 - Prob. 41PCh. 3.1 - Prob. 42PCh. 3.1 - Prob. 43PCh. 3.1 - Prob. 44PCh. 3.1 - Prob. 45PCh. 3.1 - Prob. 46PCh. 3.1 - Prob. 47PCh. 3.1 - Prob. 48PCh. 3.1 - Prob. 49PCh. 3.1 - Prob. 50PCh. 3.1 - Prob. 51PCh. 3.1 - Prob. 52PCh. 3.1 - Prob. 53PCh. 3.1 - Prob. 54PCh. 3.1 - Prob. 55PCh. 3.1 - Prob. 56PCh. 3.2 - Prob. 1PCh. 3.2 - Prob. 2PCh. 3.2 - Prob. 3PCh. 3.2 - Prob. 4PCh. 3.2 - Prob. 5PCh. 3.2 - Prob. 6PCh. 3.2 - Prob. 7PCh. 3.2 - Prob. 8PCh. 3.2 - Prob. 9PCh. 3.2 - Prob. 10PCh. 3.2 - Prob. 11PCh. 3.2 - Prob. 12PCh. 3.2 - Prob. 13PCh. 3.2 - Prob. 14PCh. 3.2 - Prob. 15PCh. 3.2 - Prob. 16PCh. 3.2 - Prob. 17PCh. 3.2 - Prob. 18PCh. 3.2 - Prob. 19PCh. 3.2 - Prob. 20PCh. 3.2 - Prob. 21PCh. 3.2 - Prob. 22PCh. 3.2 - Prob. 23PCh. 3.2 - Prob. 24PCh. 3.2 - Let Ly=y+py+qy. Suppose that y1 and y2 are two...Ch. 3.2 - Prob. 26PCh. 3.2 - Prob. 27PCh. 3.2 - Prob. 28PCh. 3.2 - Prob. 29PCh. 3.2 - Prob. 30PCh. 3.2 - Prob. 31PCh. 3.2 - Prob. 32PCh. 3.2 - Prob. 33PCh. 3.2 - Assume as known that the Vandermonde determinant...Ch. 3.2 - Prob. 35PCh. 3.2 - Prob. 36PCh. 3.2 - Prob. 37PCh. 3.2 - Prob. 38PCh. 3.2 - Prob. 39PCh. 3.2 - Prob. 40PCh. 3.2 - Prob. 41PCh. 3.2 - Prob. 42PCh. 3.2 - Prob. 43PCh. 3.2 - Prob. 44PCh. 3.3 - Find the general solutions of the differential...Ch. 3.3 - Prob. 2PCh. 3.3 - Prob. 3PCh. 3.3 - Prob. 4PCh. 3.3 - Prob. 5PCh. 3.3 - Prob. 6PCh. 3.3 - Prob. 7PCh. 3.3 - Prob. 8PCh. 3.3 - Prob. 9PCh. 3.3 - Prob. 10PCh. 3.3 - Prob. 11PCh. 3.3 - Prob. 12PCh. 3.3 - Prob. 13PCh. 3.3 - Prob. 14PCh. 3.3 - Prob. 15PCh. 3.3 - Prob. 16PCh. 3.3 - Prob. 17PCh. 3.3 - Prob. 18PCh. 3.3 - Prob. 19PCh. 3.3 - Prob. 20PCh. 3.3 - Prob. 21PCh. 3.3 - Prob. 22PCh. 3.3 - Prob. 23PCh. 3.3 - Prob. 24PCh. 3.3 - Prob. 25PCh. 3.3 - Prob. 26PCh. 3.3 - Prob. 27PCh. 3.3 - Prob. 28PCh. 3.3 - Prob. 29PCh. 3.3 - Prob. 30PCh. 3.3 - Prob. 31PCh. 3.3 - Prob. 32PCh. 3.3 - Prob. 33PCh. 3.3 - Prob. 34PCh. 3.3 - Prob. 35PCh. 3.3 - Prob. 36PCh. 3.3 - Find a function y (x ) such that y(4)(x)=y(3)(x)...Ch. 3.3 - Solve the initial value problem...Ch. 3.3 - Prob. 39PCh. 3.3 - Prob. 40PCh. 3.3 - Prob. 41PCh. 3.3 - Prob. 42PCh. 3.3 - Prob. 43PCh. 3.3 - Prob. 44PCh. 3.3 - Prob. 45PCh. 3.3 - Prob. 46PCh. 3.3 - Prob. 47PCh. 3.3 - Prob. 48PCh. 3.3 - Solve the initial value problem...Ch. 3.3 - Prob. 50PCh. 3.3 - Prob. 51PCh. 3.3 - Prob. 52PCh. 3.3 - Prob. 53PCh. 3.3 - Prob. 54PCh. 3.3 - Prob. 55PCh. 3.3 - Prob. 56PCh. 3.3 - Prob. 57PCh. 3.3 - Prob. 58PCh. 3.4 - Prob. 1PCh. 3.4 - Prob. 2PCh. 3.4 - Prob. 3PCh. 3.4 - Prob. 4PCh. 3.4 - Prob. 5PCh. 3.4 - Prob. 6PCh. 3.4 - Prob. 7PCh. 3.4 - Prob. 8PCh. 3.4 - Prob. 9PCh. 3.4 - Prob. 10PCh. 3.4 - Prob. 11PCh. 3.4 - Prob. 12PCh. 3.4 - Prob. 13PCh. 3.4 - Prob. 14PCh. 3.4 - Prob. 15PCh. 3.4 - Prob. 16PCh. 3.4 - Prob. 17PCh. 3.4 - Prob. 18PCh. 3.4 - Prob. 19PCh. 3.4 - Prob. 20PCh. 3.4 - Prob. 21PCh. 3.4 - Prob. 22PCh. 3.4 - Prob. 23PCh. 3.4 - Prob. 24PCh. 3.4 - Prob. 25PCh. 3.4 - Prob. 26PCh. 3.4 - Prob. 27PCh. 3.4 - Prob. 28PCh. 3.4 - Prob. 29PCh. 3.4 - Prob. 30PCh. 3.4 - Prob. 31PCh. 3.4 - Prob. 32PCh. 3.4 - Prob. 33PCh. 3.4 - Prob. 34PCh. 3.4 - Prob. 35PCh. 3.4 - Prob. 36PCh. 3.4 - Prob. 37PCh. 3.4 - Prob. 38PCh. 3.5 - In Problems 1 through 20, find a particular...Ch. 3.5 - Prob. 2PCh. 3.5 - Prob. 3PCh. 3.5 - Prob. 4PCh. 3.5 - Prob. 5PCh. 3.5 - Prob. 6PCh. 3.5 - Prob. 7PCh. 3.5 - Prob. 8PCh. 3.5 - Prob. 9PCh. 3.5 - Prob. 10PCh. 3.5 - Prob. 11PCh. 3.5 - Prob. 12PCh. 3.5 - Prob. 13PCh. 3.5 - Prob. 14PCh. 3.5 - Prob. 15PCh. 3.5 - Prob. 16PCh. 3.5 - Prob. 17PCh. 3.5 - Prob. 18PCh. 3.5 - Prob. 19PCh. 3.5 - Prob. 20PCh. 3.5 - Prob. 21PCh. 3.5 - Prob. 22PCh. 3.5 - Prob. 23PCh. 3.5 - Prob. 24PCh. 3.5 - Prob. 25PCh. 3.5 - Prob. 26PCh. 3.5 - Prob. 27PCh. 3.5 - Prob. 28PCh. 3.5 - Prob. 29PCh. 3.5 - Prob. 30PCh. 3.5 - Prob. 31PCh. 3.5 - Prob. 32PCh. 3.5 - Prob. 33PCh. 3.5 - Prob. 34PCh. 3.5 - Prob. 35PCh. 3.5 - Prob. 36PCh. 3.5 - Prob. 37PCh. 3.5 - Prob. 38PCh. 3.5 - Prob. 39PCh. 3.5 - Prob. 40PCh. 3.5 - Prob. 41PCh. 3.5 - Prob. 42PCh. 3.5 - Prob. 43PCh. 3.5 - Prob. 44PCh. 3.5 - Prob. 45PCh. 3.5 - Prob. 46PCh. 3.5 - Prob. 47PCh. 3.5 - Prob. 48PCh. 3.5 - Prob. 49PCh. 3.5 - Prob. 50PCh. 3.5 - Prob. 51PCh. 3.5 - Prob. 52PCh. 3.5 - Prob. 53PCh. 3.5 - Prob. 54PCh. 3.5 - Prob. 55PCh. 3.5 - Prob. 56PCh. 3.5 - You can verify by substitution that yc=c1x+c2x1 is...Ch. 3.5 - Prob. 58PCh. 3.5 - Prob. 59PCh. 3.5 - Prob. 60PCh. 3.5 - Prob. 61PCh. 3.5 - Prob. 62PCh. 3.5 - Prob. 63PCh. 3.5 - Prob. 64PCh. 3.6 - Prob. 1PCh. 3.6 - Prob. 2PCh. 3.6 - Prob. 3PCh. 3.6 - Prob. 4PCh. 3.6 - Prob. 5PCh. 3.6 - Prob. 6PCh. 3.6 - Prob. 7PCh. 3.6 - Prob. 8PCh. 3.6 - Prob. 9PCh. 3.6 - Prob. 10PCh. 3.6 - Prob. 11PCh. 3.6 - Prob. 12PCh. 3.6 - Prob. 13PCh. 3.6 - Prob. 14PCh. 3.6 - Each of Problems 15 through 18 gives the...Ch. 3.6 - Prob. 16PCh. 3.6 - Prob. 17PCh. 3.6 - Prob. 18PCh. 3.6 - A mass weighing 100 lb (mass m=3.125 slugs in fps...Ch. 3.6 - Prob. 20PCh. 3.6 - Prob. 21PCh. 3.6 - Prob. 22PCh. 3.6 - Prob. 23PCh. 3.6 - A mass on a spring without damping is acted on by...Ch. 3.6 - Prob. 25PCh. 3.6 - Prob. 26PCh. 3.6 - Prob. 27PCh. 3.6 - Prob. 28PCh. 3.6 - Prob. 29PCh. 3.6 - Prob. 30PCh. 3.7 - Problems 1 through 6 deal with the RL circuit of...Ch. 3.7 - Problems 1 through 6 deal with the RL circuit of...Ch. 3.7 - Problems 1 through 6 deal with the RL circuit of...Ch. 3.7 - Problems 1 through 6 deal with the RL circuit of...Ch. 3.7 - Problems 1 through 6 deal with the RL circuit of...Ch. 3.7 - Problems 1 through 6 deal with the RL circuit of...Ch. 3.7 - Problems 7 through 10 deal with the RC circuit in...Ch. 3.7 - Problems 7 through 10 deal with the RC circuit in...Ch. 3.7 - Problems 7 through 10 deal with the RC circuit in...Ch. 3.7 - Problems 7 through 10 deal with the RC circuit in...Ch. 3.7 - In Problems 11 through 16, the parameters of an...Ch. 3.7 - In Problems 11 through 16, the parameters of an...Ch. 3.7 - In Problems 11 through 16, the parameters of an...Ch. 3.7 - In Problems 11 through 16, the parameters of an...Ch. 3.7 - In Problems 11 through 16, the parameters of an...Ch. 3.7 - In Problems 11 through 16, the parameters of an...Ch. 3.7 - In Problems 17 through 22, an RLC circuit with...Ch. 3.7 - In Problems 17 through 22, an RLC circuit with...Ch. 3.7 - In Problems 17 through 22, an RLC circuit with...Ch. 3.7 - In Problems 17 through 22, an RLC circuit with...Ch. 3.7 - In Problems 17 through 22, an RLC circuit with...Ch. 3.7 - In Problems 17 through 22, an RLC circuit with...Ch. 3.7 - Consider an LC circuit—that is, an RLC circuit...Ch. 3.7 - Prob. 24PCh. 3.7 - Prob. 25PCh. 3.8 - Prob. 1PCh. 3.8 - Prob. 2PCh. 3.8 - Prob. 3PCh. 3.8 - Prob. 4PCh. 3.8 - Prob. 5PCh. 3.8 - Prob. 6PCh. 3.8 - Prob. 7PCh. 3.8 - Prob. 8PCh. 3.8 - Prob. 9PCh. 3.8 - Prove that the eigenvalue problem...Ch. 3.8 - Prob. 11PCh. 3.8 - Prob. 12PCh. 3.8 - Prob. 13PCh. 3.8 - Prob. 14PCh. 3.8 - A uniform cantilever beam is fixed at x=0 and free...Ch. 3.8 - Suppose that a beam is fixed at its ends...Ch. 3.8 - For the simply supported beam whose deflection...Ch. 3.8 - A beam is fixed at its left end x=0 but is simply...
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- Total marks 15 4. : Let f R2 R be defined by f(x1, x2) = 2x²- 8x1x2+4x+2. Find all local minima of f on R². [10 Marks] (ii) Give an example of a function f R2 R which is neither bounded below nor bounded above, and has no critical point. Justify briefly your answer. [5 Marks]arrow_forward4. Let F RNR be a mapping. (i) x ЄRN ? (ii) : What does it mean to say that F is differentiable at a point [1 Mark] In Theorem 5.4 in the Lecture Notes we proved that if F is differentiable at a point x E RN then F is continuous at x. Proof. Let (n) CRN be a sequence such that xn → x ЄERN as n → ∞. We want to show that F(xn) F(x), which means F is continuous at x. Denote hnxn - x, so that ||hn|| 0. Thus we find ||F(xn) − F(x)|| = ||F(x + hn) − F(x)|| * ||DF (x)hn + R(hn) || (**) ||DF(x)hn||+||R(hn)||| → 0, because the linear mapping DF(x) is continuous and for all large nЄ N, (***) ||R(hn) || ||R(hn) || ≤ → 0. ||hn|| (a) Explain in details why ||hn|| → 0. [3 Marks] (b) Explain the steps labelled (*), (**), (***). [6 Marks]arrow_forward4. In Theorem 5.4 in the Lecture Notes we proved that if F: RN → Rm is differentiable at x = RN then F is continuous at x. Proof. Let (xn) CRN be a sequence such that x → x Є RN as n → ∞. We want F(x), which means F is continuous at x. to show that F(xn) Denote hn xnx, so that ||hn||| 0. Thus we find ||F (xn) − F(x) || (*) ||F(x + hn) − F(x)|| = ||DF(x)hn + R(hn)|| (**) ||DF(x)hn|| + ||R(hn) || → 0, because the linear mapping DF(x) is continuous and for all large n = N, |||R(hn) || ≤ (***) ||R(hn)|| ||hn|| → 0. Explain the steps labelled (*), (**), (***) [6 Marks] (ii) Give an example of a function F: RR such that F is contin- Total marks 10 uous at x=0 but F is not differentiable at at x = 0. [4 Marks]arrow_forward
- 3. Let f R2 R be a function. (i) Explain in your own words the relationship between the existence of all partial derivatives of f and differentiability of f at a point x = R². (ii) Consider R2 → R defined by : [5 Marks] f(x1, x2) = |2x1x2|1/2 Show that af af -(0,0) = 0 and -(0, 0) = 0, Jx1 მx2 but f is not differentiable at (0,0). [10 Marks]arrow_forward(1) Write the following quadratic equation in terms of the vertex coordinates.arrow_forwardThe final answer is 8/π(sinx) + 8/3π(sin 3x)+ 8/5π(sin5x)....arrow_forward
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