Mark (√) against the correct answer in the following:
is decreasing for all 
, when
f(x) =sin x - kx
f’(x) = cos x –k
∴ f decreases, if f’(x)≤ 0
⇒ cos x – k ≤ 0
⇒ cos x≤ k
So, for decreasing k≥ 1.
1
Mark (√) against the correct answer in the following:
is decreasing for all , when
f(x) =sin x - kx
f’(x) = cos x –k
∴ f decreases, if f’(x)≤ 0
⇒ cos x – k ≤ 0
⇒ cos x≤ k
So, for decreasing k≥ 1.