For f(x, y) = xy² + x³ + y³ + 2xy, find the partial derivative ∂f/∂y at the point (1, 2).
Multivariable calculus worksheet with answers
1.Easy
f(x, y) = xy² + x³ + y³ + 2xyP = (1, 2)
fy(1, 2) =
2.Easy
For f(x, y) = 2y·e2xy, find the partial derivative ∂f/∂y at the point (0.5, 2).
f(x, y) = 2y·e2xyP = (0.5, 2)
fy(0.5, 2) =
3.Medium
For f(x, y) = 2y·exy, find the direction of steepest ascent at (2, 2) as the angle θ from the positive x-axis, in degrees between −180° and 180°.
f(x, y) = 2y·exyP = (2, 2)
θ = °
4.Medium
The tangent plane to z = 2xe0.5y at the point where (x, y) = (1, 1) can be written as z = px + qy + c. Find c.
f(x, y) = 2xe0.5y(a, b) = (1, 1)
c =
5.Hard
Find the critical points of f(x, y) = x³ − 3x + y², classify them, and give the value fmin of f at its local minimum.
f(x, y) = x³ − 3x + y²
fmin =
6.Hard
Evaluate I = ∬T (2x − y) dA over the triangle T bounded by y = 0, x = 3 and y = 3x.
f = 2x − y0 ≤ x ≤ 30 ≤ y ≤ 3x
I =
Answer key
- 1. fy(1, 2) = 18
- 2. fy(0.5, 2) = 44.33
- 3. θ = 51.34 °
- 4. c = −1.649
- 5. fmin = −2
- 6. I = 13.5
Full step-by-step solutions: practise this topic on examproblems.com.