a) Find an equation on the tangent line to the graph of y=g(x) at x= 5 if g(5) = -3 and g'(5) = 4
b) If the tangent line to y = f(x) at (4,3) passes through the point (0,2), find f(4) and f'(4)
Indeed, the veracity/validity/whatever of the point slope formula should not be called into question at this juncture. So we're left with the task of finding a point and a slope, in order to determine the desired line.
Welp, g(5)=-3 means that (5, -3) is the point.
And you really DO need to know that the slope of the tangent is given by the derivative.