Question

1.tga*ctg-cos^2a=

2.sin^3a+sina*cos^2atga=

3.sin^2a+2cos^2a-1=

4.3sin0+2cos0=

5.1+tg(3 pi2+a)*sina

Answer 1

1. (sin a/ cos a )(cosa/sina)-cos^2 a = 1- cos^2 a=sin^2 a

3. Sin ^2 a+ 2 cos ^2 a -1

sin^2 a= 1 - cos^2 a, поэтому : 1-cos^2 a +2 cos^2 a -1=cos^2a

4. sin 0=1

cos 0=1   3*1+2*1=5