1) cos^2a*tg^2a+5cos^2a-1 2) sina+3sin^2a+3cos^2a

Question

1) cos^2a*tg^2a+5cos^2a-1
2) sina+3sin^2a+3cos^2a

Answer 1

1)cos²αtg²α+5cos²α-1=cos²α*(sin²α/cos²α)+5cos²α-(sin²α+cos²α)= sin²α+5cos²α-sin²α-cos²α=4cos²α
2) sinα+3sin²α+3cos²α=sinα+3(sin²α+cos²α)=sinα+3

Comments

отлично))