Question

use the second derivative test to locate all relative extrema and inflection points of f(x)=x-sinx for 0 13 years ago

Answer 1

f'(x) = 1 - cosx
for turning points
1 - cosx = 0
cos x = 1
x = 0, 2pi

f"(x) = sinx
when x = 0 , sin x = 0
when x = 2pi sin x = 0

these are points of inflection

hope this helps - i'm a bit rusty at this stuff!!

Answer 2

oh its less than or = to so there another value of x at 4pi