For f(x, y) = sin(−x + y), find the partial derivative ∂f/∂x at the point (1, 2).
Multivariable calculus worksheet with answers
1.Easy
f(x, y) = sin(−x + y)P = (1, 2)
fx(1, 2) =
2.Easy
Evaluate I = ∫13 ∫24 (3x·ey) dy dx over the rectangle 1 ≤ x ≤ 3, 2 ≤ y ≤ 4.
f = 3x·ey1 ≤ x ≤ 32 ≤ y ≤ 4
I =
3.Medium
The tangent plane to z = 2x³e−y at the point where (x, y) = (−1, 0.5) can be written as z = px + qy + c. Find c.
f(x, y) = 2x³e−y(a, b) = (−1, 0.5)
c =
4.Medium
Use the tangent plane of f(x, y) = −3x³y² − x² − 2y² + xy at (3, 1) to approximate f(2.8, 0.8). Give the linear approximation L.
f(x, y) = −3x³y² − x² − 2y² + xy(a, b) = (3, 1)(x, y) = (2.8, 0.8)
L =
5.Hard
The marked points are the critical points of f(x, y) = −x³ + 3x − y² + 6y. Click the saddle point.
f(x, y) = −x³ + 3x − y² + 6y
- 1A (1, 3)
- 2B (−1, 3)
6.Hard
Use polar coordinates to evaluate I = ∬R y dA, where R is the upper half of the disc x² + y² ≤ 1 (y ≥ 0).
f = y0 ≤ r ≤ 10 ≤ θ ≤ π
I =
Answer key
- 1. fx(1, 2) = −0.5403
- 2. I = 566.5
- 3. c = 1.82
- 4. L = −39.2
- 5. B (−1, 3)
- 6. I = 0.6667
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