Question

14. 14. If f(x)= sec^2x, thenf'(x)=

Answer 1

1 (2) f(x) = 1 (3) 1< f(x) < 2 (4) f(x) greater than or equal to 2

Explanation:

We know AM ≥ GM

(cos2x+sec2x )/2 ≥ √(cos2x sec2x)

(cos2x+sec2x ) ≥ 2√(cos2x (1/cos2x)

f(x) ≥ 2

Hence option (4) is the answer.