Question

Помогите пожалуйста срочно.Упростите:

Answer 1

1) $sin^{2}(402)+sin^{2}48+tg^{2}225=sin^{2}(402-360)+sin^{2}48+tg^{2}(225-180)=sin^{2}42+sin^{2}48+tg^{2}45=sin^{2}(45-3)+sin^{2}(45+3)+1=(sin45*cos3-cos45*sin3)^{2}+(sin45*cos3+cos45*sin3)^{2}+1=2sin^{2}45*cos^{2}3+2cos^{2}45*sin^{2}3+1=cos^{2}3+sin^{2}3+1=1+1=2$

2) $sin^{2}99+cos^{2}81+ctg^{2}135=sin^{2}(90+9)+cos^{2}(90-9)+ctg^{2}(180-45)=(sin90*cos9+sin9*cos90)^{2}+(cos90*cos9+sin90*sin9)^{2}+ctg^{2}45=cos^{2}9+sin^{2}9+1=1+1=2$