Edit: never mind, found an answer via http://www.nabla.hr/Z_MemoHU-029.htm
I was stuck on a question from FP3 and found that the online solution used the formula:
b^2 + (a^2)(m^2) = c^2.
Any idea where this comes from? I can't find it in the book and I'm fairly sure it can't be derived from the two equations given.
Have I left it too late?