Find an equation of the tangent line to the curve y x x that is parallel to the line y 3 9x y x 12x 12 X Enhanced Feedback Please try again Find the derivative of the function set it equal to the slope of the given line then solve for x This will give you the x coordinate of the point at which the tangent line is parallel to the find the tangent line Remember that the slopes of two parallel lines are equal and the slope of the line y f a f a x a is f a