1.

The equation of the tangent at (2, 3) on the curve y2 = ax3 + b is y = 4x – 5. Find the values of a and b.

Answer»

Given as y2 = ax3 + b is y = 4x – 5

Differentiate the given curve, to get the slope of tangent

2y(dy/dx) = 3ax2

dy/dx = 3ax2/2y

m(tangent) at (2, 3) = 2a

The equation of tangent is given by y – y1 = m (tangent) (x – x1)

Comparing the slope of a tangent with the given equation

2a = 4

a = 2

(2, 3) lies on the curve, these points must satisfy

32 = 2 × 23 + b

b = – 7



Discussion

No Comment Found