Lets work on the left side of the equation. Combine the 2 fractions with a common denominator of (sinx)(cosx)with gives us
(sin^2x+cos^2x)/ (sinx)(cosx) use the identity sin^2x +cos^2= 1 to give you
1/(sinx0(cosx) which is the same as (1/sin)(1/cosx)
1/sinx = csc x and 1/cosx = secx
(cscx) (secx0 = (cscx) (secx)