Thread: Basic and easy Derivative question

If the line normal to the graph of f at the point (1,2) passes through the point (-1,1),

then what is the value of f'(1)=?

Question seems to be pretty easy and legitimate but some reason i dont get this problem...

ahh I just started to learn limits and Derivatives, please help me

Originally Posted by kevinoh92

If the line normal to the graph of f at the point (1,2) passes through the point (-1,1),

then what is the value of f'(1)=?

Question seems to be pretty easy and legitimate but some reason i dont get this problem...

ahh I just started to learn limits and Derivatives, please help me

slope of the tangent line is perpendicular to the slope of the normal line ... what is the relationship between perpendicular slopes?