How would you solve a reduction identity. For example cot(x-90)? What are the steps to solving them besides graphing?
you could say
cot(x-90°) = tan(-x) = -tanx
there are 3 pairs of co-ratios
sine vs co-sine
tangent vs co-tangent
secant vs co-secant
for each of these
trigratio(x) = co-trigratio(90°-x)
Don't know if this answers your question.