f(x) = coses x in (-π, 0) has a maxima atA. x = 0B. x = -π/4C. x = -

1.	f(x) = coses x in (-π, 0) has a maxima atA. x = 0B. x = -π/4C. x = -π/3D. x = -π/2
Answer» Answer is : D. x = -π/2 We can go through options for this question Option a is wrong because 0 is not included in (-π,0) At x = -π/4 value of f(x) is -√2 = -1.41 At x = -π/3 value of f(x) is -2. At x = -π/2 value of f(x) is -1. ∴ f(x) has max value at x = -π/2. Which is -1.

f(x) = coses x in (-π, 0) has a maxima atA. x = 0B. x = -π/4C. x = -π/3D. x = -π/2

Answer»

Answer is : D. x = -π/2

We can go through options for this question

Option a is wrong because 0 is not included in (-π,0)

At x = -π/4 value of f(x) is -√2 = -1.41

At x = -π/3 value of f(x) is -2.

At x = -π/2 value of f(x) is -1.

∴ f(x) has max value at x = -π/2.

Which is -1.