Question

упростить
sin^4 a- cos ^4 a - sin^2 a + cos^2 a ​

Answer 1

Ответ: 0

$sin^4 a- cos ^4 a - sin^2 a + cos^2 a=\=(sin^2 a+ cos ^2 a)*(sin^2 a- cos ^2 a)-sin^2 a + cos^2 a=\=1*(sin^2 a- cos ^2 a)-sin^2 a + cos^2 a=0$