Trig functions in terms of x,y, and r?

1. May 6, 2015

Tyrion101

I work a good deal better when the equation is in x and y form, is it possible to set up a trig expression like 5Cos(x)/(Sin(x)-1)and substitute the proper x or y equivalent so long as I remember to replace the trig identities later when the problem is finished? Or can you just not solve these problems like this?

2. May 6, 2015

Raghav Gupta

Yeah, you can substitute,
Take sin x = y,
Then what should be cosx in terms of y ?

3. May 6, 2015

By proper x or y equivalent'' do you mean the types of definitions for sine and cosine we commonly attach to their definitions from triangles or unit circles? I' not sure what you're meaning is, or of the type of problem you are intending to solve