I have a homework problem as follows: If the tangent line to y = f(x) at (4,3) passes through the point (0,2), find f(4) and f'(4). Using the slope formula and the point-slope formula, I found that the equation of the given tangent line is y = 1/4x + 2. Now I want to find f(x) so I can actually answer the question. I thought I might be able to solve for f(x) using the equation f'(a)= lim [f(x+h) - f(x)]/h h-->0 and subsituting 1/4 for f'(a), but I can't get any farther than setting that up. help? please? thanks!