Question

упростите выражение:
(sin a - cos a) ² + (sin a + cos a) ² - 2

Answer 1

(sin(a) - cos(a) ) ² + (sin(a) + cos(a) ) ² - 2 =

= sin²(a) -2sin(a) cos(a) +cos²(a) + sin²(а)+ 2sin(a)cos(a)+ cos²(а) - 2=

= 1+1-2=0