1.已知函数f(x)满足f(tanα)=tan2α,则f(2)=
问题描述:
1.已知函数f(x)满足f(tanα)=tan2α,则f(2)=
答
f(tanα)
= tan2α
= 2tanα/(1 - tan²α)
所以 f(x) = 2x/(1 - x²)
所以 f(2) = 4/(1 - 4) = -4/3