已知tan(a+π\4)=3,求(1+sin4a-cos4a)\(1+sin4a+cos4a)的值.

网友回答

tan(a+π/4)=3,
(tana+1)/(1- tana)=3, tana=1/2.
tan2a=2 tana/(1- tan²a)=4/3.
(1+sin4a-cos4a)/(1+sin4a+cos4a)
=(1 -cos4a+sin4a)/(1 +cos4a+sin4a)
=(2sin²2a+2sin2acos2a)/( 2cos²2a+2sin2acos2a)
=2sin2a(sin2a+cos2a)/[ 2cos2a(sin2a+cos2a)]
= tan2a=4/3.
======以下答案可供参考======
供参考答案1:
0.5