Question

Find points at which the tangent to the curve y = x³ – 3x² – 9x + 7 is parallel to the x-axis.

Answer 1

Answer:

Let at (a,b) , y is parallel to the x - axis. hence, (3, -20) and (-1, 12) are the point at which the tangent to the curve, y = x³ - 3x² - 9x + 7 is parallel to the axis.