How do you solve cot^2x-cscx=1 and find all solutions in the interval 0<=x<360?

1 Answer
Oct 17, 2016

cos^2x/sin^2x - 1/sinx = 1

cos^2x/sin^2x -sinx/sin^2x - sin^2x/sin^2x = 0

cos^2x -sinx - sin^2x = 0

Apply the identity cos^2x = 1 - sin^2x.

1 - sin^2x - sinx - sin^2x = 0

-2sin^2x - sinx + 1 = 0

-2sin^2x - 2sinx + sinx + 1 = 0

-2sinx(sinx + 1) + 1(sinx + 1) =0

(-2sinx + 1)(sinx + 1) = 0

sinx =-1/2 and sinx = -1

x = 210˚, 330˚, 270˚

Hopefully this helps!