Question

The tangent to the curve (x –2)⁴ + ( y – 1)⁴ = 81 at the point (5, 1) is -

• A. 2x + y = 1
• B. x + 5y = 10
• C. y = 1
• D. x = 5

Answer 1

Answer: (D)

x = 5

Answer 2

4 (x – 2)³ + 4 (y – 1)³ $\left( \frac{dy}{dx} \right)$ = 0

̃ $\left( \frac{dy}{dx} \right)_{(5,1)} = \frac{- (x - 2)^{3}}{(y - 1)^{3}}$ = ¥

The equation is x = 5