# Math Help - simple integration.

1. ## simple integration.

The gradient of a curve is dy/dx=kx, where k is constant.
y=6x-7 and y=mx+c are the equation of the tangent and normal to the curve respectively. Find the values of m and c.

m is solved easily. but couldn't find out what's c.
Any help would be so much appreciated!
If dy/dx= kx, then $y= \frac{1}{2}x^2+ C$. If y= 6x- 7 is tangent to that, what is C and where is the line tangent to the curve? What must c be in order that y= mx+ c pass through that point?