1.

Show that f(x) = x – sin x is increasing for all x ϵ R.

Answer»

Given as f(x) = x – sin x

f'(x) = (d/dx)(x - sin x)

⇒ f’(x) = 1 – cos x

As given x ϵ R

⇒ –1 < cos x < 1

⇒ –1 > cos x > 0

⇒ f’(x) > 0

Thus, condition for f(x) to be increasing

Hence, f(x) is increasing on interval x ∈ R



Discussion

No Comment Found