Ok, I've found the answer to these questions, but I did so in more of a trial and error way. The question is:
f(x) = 2x^2 + x
Find the two tangent lines to the curve, which both pass through the point (2,-3).
So, I tried using y=mx+b = 2x^2 + x, where m = f'(x) = 2x + 1, thus:
(2x+1)x...