Consider the function f(x, y) = (eª — 4x) cos(y). Suppose S is the surface z = f(x, y). (a) Find a vector which is perpendicular to the level curve of f through the point (2, 3) in the direction in which f decreases most rapidly. vector = -(e^2 - 4) cos(3) i - ( e^2 - 12) sin (3) j (b) Suppose 7 = 27 +33 + ak is a vector in 3-space which is tangent to the surface S at the point P lying on the surface above (2, 3). What is a? a = 2(e^2 - 4) cos(3) -3(e^2 - 12)sin (3)

Advanced Engineering Mathematics
10th Edition
ISBN:9780470458365
Author:Erwin Kreyszig
Publisher:Erwin Kreyszig
Chapter2: Second-order Linear Odes
Section: Chapter Questions
Problem 1RQ
icon
Related questions
Question

1.11

 

please solve it on paper 

**Consider the function \( f(x, y) = (e^x - 4x) \cos(y) \). Suppose \( S \) is the surface \( z = f(x, y) \).**

### (a) Find a vector which is perpendicular to the level curve of \( f \) through the point \( (2,3) \) in the direction in which \( f \) decreases most rapidly.

**Solution:**
The vector perpendicular to the level curve of \( f \) through the point \( (2,3) \) is given by the gradient of \( f \) evaluated at \( (2,3) \). It is in the direction in which \( f \) decreases most rapidly.

\[ 
\text{vector} = -(e^2 - 4) \cos(3) \mathbf{i} - ( e^2 - 12) \sin (3) \mathbf{j} 
\]

### (b) Suppose \( \vec{v} = 2\mathbf{i} + 3\mathbf{j} + a\mathbf{k} \) is a vector in 3-space which is tangent to the surface \( S \) at the point \( P \) lying on the surface above \( (2,3) \). What is \( a \)?

**Solution:**
We need to find the value of \( a \) such that the vector \( \vec{v} = 2\mathbf{i} + 3\mathbf{j} + a\mathbf{k} \) is tangent to the surface \( S \) at the point above \( (2,3) \).

\[ 
a = 2( e^2 - 4) \cos(3) - 3( e^2 - 12)\sin (3) 
\]
Transcribed Image Text:**Consider the function \( f(x, y) = (e^x - 4x) \cos(y) \). Suppose \( S \) is the surface \( z = f(x, y) \).** ### (a) Find a vector which is perpendicular to the level curve of \( f \) through the point \( (2,3) \) in the direction in which \( f \) decreases most rapidly. **Solution:** The vector perpendicular to the level curve of \( f \) through the point \( (2,3) \) is given by the gradient of \( f \) evaluated at \( (2,3) \). It is in the direction in which \( f \) decreases most rapidly. \[ \text{vector} = -(e^2 - 4) \cos(3) \mathbf{i} - ( e^2 - 12) \sin (3) \mathbf{j} \] ### (b) Suppose \( \vec{v} = 2\mathbf{i} + 3\mathbf{j} + a\mathbf{k} \) is a vector in 3-space which is tangent to the surface \( S \) at the point \( P \) lying on the surface above \( (2,3) \). What is \( a \)? **Solution:** We need to find the value of \( a \) such that the vector \( \vec{v} = 2\mathbf{i} + 3\mathbf{j} + a\mathbf{k} \) is tangent to the surface \( S \) at the point above \( (2,3) \). \[ a = 2( e^2 - 4) \cos(3) - 3( e^2 - 12)\sin (3) \]
Expert Solution
trending now

Trending now

This is a popular solution!

steps

Step by step

Solved in 4 steps with 4 images

Blurred answer
Recommended textbooks for you
Advanced Engineering Mathematics
Advanced Engineering Mathematics
Advanced Math
ISBN:
9780470458365
Author:
Erwin Kreyszig
Publisher:
Wiley, John & Sons, Incorporated
Numerical Methods for Engineers
Numerical Methods for Engineers
Advanced Math
ISBN:
9780073397924
Author:
Steven C. Chapra Dr., Raymond P. Canale
Publisher:
McGraw-Hill Education
Introductory Mathematics for Engineering Applicat…
Introductory Mathematics for Engineering Applicat…
Advanced Math
ISBN:
9781118141809
Author:
Nathan Klingbeil
Publisher:
WILEY
Mathematics For Machine Technology
Mathematics For Machine Technology
Advanced Math
ISBN:
9781337798310
Author:
Peterson, John.
Publisher:
Cengage Learning,
Basic Technical Mathematics
Basic Technical Mathematics
Advanced Math
ISBN:
9780134437705
Author:
Washington
Publisher:
PEARSON
Topology
Topology
Advanced Math
ISBN:
9780134689517
Author:
Munkres, James R.
Publisher:
Pearson,