Упростите
1. cos²a+1 / 2-2sin²a
2. 2sinacosa / cos²a-sin²a+1

Объяснение:

1)  cos2a +1 / 2-2sin^2 a =cos^2 a -sin^2 a+cos^2 a +sin^2 a /2(1-sin^2 a) =

2cos^ a / 2cos^2 a=1

2) 2sinacosa / cos^2 a-sin^2 a+sin^2 a+cos^2 a =2sinacosa /2cos^2 a=

sina/cosa =tga