1. The problem statement, all variables and given/known data I was working on a problem set involving greens theorem and I came across this peculiar trig substitution. I was just wondering how it came about as I couldn't find anything like it on Wikipedia's page. [itex] sin^4(t)cos^2(t) + cos^4(t) sin^2(t) = cos^2(t)sin^2(t) [/itex] 3. The attempt at a solution I tried using the basic's such as [itex] (cos^2(t))^2 = (1 - sin^2(t))^2 [/itex] along with [itex] (sin^2(t))^2 = (1 - cos^2(t))^2[/itex] which after some substitution gives [itex] cos^6(t) - cos^4(t) + sin^2(t)cos^2(t) + sin^6(t) - sin^4(t) + sin^2(t)cos^2(t) [/itex] Which is close to what I wanted, but I started to get the feeling that the path I was going down wasn't going to yield my identity. Can anyone shed some light?