A tangent equation of the curve y = x ^ 2 is 4x-y-4 = 0, and the tangent coordinates are obtained

A tangent equation of the curve y = x ^ 2 is 4x-y-4 = 0, and the tangent coordinates are obtained

The slope of the curve y = x ^ 2 is y = 2x
If a tangent equation is 4x-y-4 = 0, the slope is 4, so
So 2x = 4, x = 2
That is, the abscissa of tangent point x = 2
Then the ordinate is y = x ^ 2 = 2 ^ 2 = 4
So the tangent coordinates are (2,4)