Mark the correct alternative in the following:

Function f(x) = cosx – 2λ x is monotonic decreasing when

Formula:- (i) The necessary and sufficient condition for differentiable function defined on (a,b) to be strictly decreasing on (a,b) is that f’(x)<0 for all x(a,b)

Given:-

f(x) = cosx – 2λ x

=-sinx-2λ =f’(x)

for decreasing function f’(x)<0

-sinx-2λ <0

Sinx+2λ >0

2λ>-sinx

2λ>1

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