Question

The abscissae of the points, where the tangent to curve `y = x^3 - 3/2x^2 - 6x + 7/5` is parallel to X-axis, are ______ 

विकल्प

• x = 0 and 1

• x = 1 and -1

• x = 1 and -2

• x = -1 and 2

Answer 1

The abscissae of the points, where the tangent to curve `y = x^3 - 3/2x^2 - 6x + 7/5` is parallel to X-axis, are x = -1 and 2.

Explanation:

`y = x^3 - 3/2x^2 - 6x + 7/5 ⇒ dy/dx = 3x^2 - 3x - 6`

Since the tangent is parallel to X-axis, `dy/dx = 0`

⇒ 3x² - 3x - 6 = 0 ⇒ x = -1, 2