#### Answer

$\frac{dy}{dx}=\frac{x}{c}$

#### Work Step by Step

Differentiate the equation in respect to $x$, remembering to use chain rule. $$2c\frac{dy}{dx}=2x$$ Solve for the slope of the tangent line $\frac{dy}{dx}$ to get a slope of $$\frac{dy}{dx}=\frac{x}{c}$$