Exam Questions Papers - Engineering

Q1:

For real values of x, the minimum value of the function f(x) exp (x) + exp (- x) is

A 2

B 1

C 0.5

D 0

ANS:A - 2

f(x) = ex + e-x f(x) = ex - ex f(x) = 0 ⇒ ex - e-x = 0 f'(x) = ex + e-x ⇒ +ve for x = 0 Thus minimum. Minimum f(x) = e0 + e0 = 2.