Question

Use basic identities and algebra to simplify the expression. Assume all denominators are nonzero. (sin t - cost t)^2

Answer 1

I would say. (sin t - cos t)^2 means (sin t - cos t)(sin t - cos t)
Using the foil method you would get sin^2t - 2sintcost + cos^2t
There is a trig identity that says sin^2t + cos^2t = 1 so since you have a sin^2t + cos ^2t then you would substitute a "1" for those terms and end up with
1 - 2sin t cos t

Answer 2

thanks!