Question

помогите решить:
10sin^4a-10cos^4a+7

Answer 1

10sin⁴α-10cos⁴α+7=10*(sin⁴α-cos⁴α)+7=10*(sin²α-cos²α)(sin²α+cos²α)+7=-10*(cos²α-sin²α)*1+7=-10*cos2α+7