I'm working with the smallest squares method using singular value decompoition to estimate a function using given data. But this is not the issue.
I know the function is of the form y = \frac{a\cdot sin(x)}{b + x\cdot sin(x+c)} but to be able to use this method, I need to rewrite it so that every parameter is standing 'alone'. By alone, I mean that it only appears in 1 term.
As you've probably guessed by now, the sin(x+c) function is the problem. It should be written so that there is only 1 term where the c-parameter occurs. If it were a simple quadratic function, it should be something like this: ax^2+bx+c.

I've already tried the classic formula to rewrite a sum of 2 angles but without any result. A second attempt was using the t-formulas and another desperate attempt was to multiply it with sin(x), sin(c), cos(c) or cos(x). All without any real result.

Can anyone tell me what I should do or at least point me in the right direction?