Question

prove csc^4x-cot^4x=2csc^2x-1

Answer 1

csc^4x-cot^4x = 2csc^2x-1
csc^4(x) - (cot^2(x))^2 = 2csc^2x-1
csc^4(x) - (csc^2(x) - 1)^2 = 2csc^2x-1
csc^4(x) - (csc^4(x) - 2csc^2(x) +1) = 2csc^2x-1
csc^4(x) - csc^4(x) + 2csc^2(x) -1 = 2csc^2x-1
2csc^2(x) - 1 = 2csc^2x-1

Medal O_O

Answer 2

Thank you!