Evaluate I = ∫13 ∫02 (xy + 1) dy dx over the rectangle 1 ≤ x ≤ 3, 0 ≤ y ≤ 2.
Multivariable calculus worksheet with answers
1.Easy
f = xy + 11 ≤ x ≤ 30 ≤ y ≤ 2
I =
2.Easy
For f(x, y) = 2 ln(x² + 4y²), find the mixed second partial derivative ∂²f/∂x∂y at (2, −1).
f(x, y) = 2 ln(x² + 4y²)P = (2, −1)
fxy(2, −1) =
3.Medium
The tangent plane to z = −x²y³ − 4x³ at the point where (x, y) = (−1, 1) can be written as z = px + qy + c. Find c.
f(x, y) = −x²y³ − 4x³(a, b) = (−1, 1)
c =
4.Medium
For f(x, y) = xey, find the maximum rate of change of f at the point (2, 0.5), that is |∇f|.
f(x, y) = xeyP = (2, 0.5)
|∇f| =
5.Hard
f(x, y) = x³ − 3x + y² + 6y has a critical point at (1, −3). Compute the discriminant D = fxxfyy − fxy² there.
f(x, y) = x³ − 3x + y² + 6yP = (1, −3)
D =
6.Hard
Evaluate I = ∬R xy dA, where R is the region between the parabola y = x² and the line y = 4x.
y = x²y = 4xf = xy
I =
Answer key
- 1. I = 12
- 2. fxy(2, −1) = 1
- 3. c = −4
- 4. |∇f| = 3.687
- 5. D = 12
- 6. I = 170.7
Full step-by-step solutions: practise this topic on examproblems.com.