Cos²α+(1-sin²α)sin²(π/2+α)+cos²(α-3π/2)/tg²(3π/2+α)ctg²(α-π/2)

Question

Cos²α+(1-sin²α)
sin²(π/2+α)+cos²(α-3π/2)/tg²(3π/2+α)ctg²(α-π/2)

Answer 1

1)cos²a+cos²a=2cos²a
2)cos²a+sin²a/tg²atg²a=1/1=1