Question

(iii) If f(x) = x2 - 5x2 + 7, find f'(1) andſ" (2).
For what values of x does f'(x) vanish?​

Answer 1

Answer:

f (1) = 3 and f (2) = - 9

f (x) = x² - 5x² + 7

= -4x² + 7

Since, it's a quadratic equation

» -4x² + 7 ≥ 0

» -4x² ≥ - 7

» 4x² ≤ 7

» x ≤ √7/2

» x ≤ 2.64/2

» x ≤ 1.32

For integral values

» x € (-∞, 1}

Hence, f (x) is vanish for x € (1, ∞)