Question

Find the value of the constant c for which the line y=2x+c is a tangent to the curve y^2 =4x.

Answer 1

I know 4x^2 - x(4c-4) +c^2
But how do carry on?

Answer 2

take the derivative of y^2=4x, set it = 2.

Answer 3

How come? And how?

Answer 4

then solve that equaion. it will give you the x,y coordinates of where the tangent line is parallel to your line y=2x+c

Answer 5

So, adter 4x^2 - x(4c-4) +c^2, how?

Answer 6

implicit differentiation...