Q8 of 149 Page 16

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.

finding the slope of the tangent by differentiating the curve




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


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


now comparing the slope of a tangent with the given equation


2a = 4


a = 2


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


32 = 2 × 23 + b


b = – 7


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