# find f(x) for the tangent line of the graph

by lalahelp
Tags: graph, line, tangent
 P: 75 1. The problem statement, all variables and given/known data Suppose line tangent to graph of y=f(x) at x =3 passes through (-3, 7) & (2,-1). Find f'(3), what is the equation of the tangent line to f at 3? 2. Relevant equations I found the slope of which equals -8/5 Im not sure how to find the equation... do I do y-3=-8/5(x-3)? or is that wrong?
 P: 615 The general form of a straight line is y=m x + c Try fitting that to your points
 P: 8 The tangent line passes through those two points. Since it is a LINE, you may use the equation to solve for the slope: m= (y2-y1) / (x2-x1) Once you have found the slope, use any of of the two coordinates to solve for 'c', the constant/y-intercept. Once you have the constant, simply write it in the form y=(#)x + (#). That is the equation of the tangent line at that point x=3.
P: 75