Question

sin+cos=0.8
Найдите sin²a×cos²a+2sina×cosa+1

Answer 1

sina+cosa=0,8
(sina+cosa)²=0,64
sin²a+2sinacosa+cos²a=0,64
1+2sinacosa=0,64
2sinacosa=0,64-1
2sinacosa=-0,36
sinacosa=-0,18
sin²acos²a=0,0324
sin²a×cos²a+2sina×cosa+1=0,0324-0,36+1=0,6724