Question

Hello guys! can you help me to solve the following problem.

Given that f(x)=Sin(x) prove that f(x+2h)-f(x)=2Cos(x+h)Sin(h)

Answer 1

since f(x)=sin x
so f(x+2)=sin(x+2h)
now f(x+2)- f(x)=sin (x+2h)-sinx
use sin c-sin d=2 sin (c+d)/2 sin (c-d)/2

Answer 2

Ahhh ok ok. That makes a lot of sense. Thanks mate. A medal for you :)