Anonymous![]() From: - Posts: - Votes: - |
If x^2 + xy + y^2 = 7, find the value of dy/dx at the point (1,2). |
Anonymous![]() From: - Posts: - Votes: - |
2x + y + xdy/dx + 2y dy/dx = 0 or dy/dx = (-2x-y)/[x+2y] at (1, 2) = -4/5 | ![]() ![]() |
Anonymous![]() From: - Posts: - Votes: - |
SOLUTION: x² + xy + y² = 7 both sides wrtx and using the product rule for the xy bit: 2x + y * 1 + x * 1 * dy/dx + 2y * dy/dx = 0 dy/dx (x + 2y) = -2x - y dy/dx = (-2x - y) / (x + 2y) and it could also be written as dy/dx = -(2x + y) / (x + 2y) At (1, 2) dy/dx = -(2 + 2) / (1 + 4) dy/dx = -4/5= answer | ![]() ![]() |