Verified answer

Ответ:

Объяснение:

2cos²(π/4 -2α)=sin4a+1

sin4a+1=2sin2α*cos2α +1=2sin2α*cos2α +sin²2α+cos²2α=(sin2a+cos2α)²

2cos²(π/4 -2α)=(√2cos(π/4 -2α))²=(√2(cosπ/4*cos2α +sinπ/4*sin2α))²= (√2(√2/2*cos2α +√2/2*sin2α))²=(√2*√2/2(cos2α +sin2α))²= (cos2α +sin2α)²