Found this "puzzle" from Strang's Calculus.

The slope-intercept form of a line (y = mx + b) requiresI'm curious on this one. Any ideas on this "puzzle"?TWOnumbers, the point-slope form (y - f(a) = f'(a)(x-a)) requiresTHREEnumbers, and the two-point form requiresFOUR(a, f(a), c, f(c)). How is this possible?

(suppose f'(a) = m).