I used the rate r=0.0825/12 to represent the monthly rate and used that for the whole equation. I final answe I got by plugging in the numbers was 29555.11248. So I'm not too sure whether or not it't correct,
1/sin^2x-1/tan^2x= 1/sin^2x-1/ (sin^2x/cos^2x)<<sin tan= sin/cos>> = 1/sin^2x- cos^2x / sin^2x = (1- cos^2x) / sin^2x <<combining into a single fraction>> sin^2 x / sin^2x <<since 1- cos^2 x sin^2 x
