f(x)=2−4sin2(x)+4sin(x)f(x)=2−4sin2(x)+4sin(x). Let t=sin(x)t=sin(x). Then 0<t≤10<t≤1. We have a new function:
f(x)=2−4sin2(x)+4sin(x)f(x)=2−4sin2(x)+4sin(x). Let t=sin(x)t=sin(x). Then 0<t≤10<t≤1. We have a new function:
g(t)=−4t2+4t+2