The equation of tangent line to the curve y = x² at (2, 4) is?

4x - y = 4

4x - 2y = 5

4x - 2y = 4

None of these

The derivative of y = x² is dy/dx = 2x.

At x = 2, the slope is 2(2) = 4.

The tangent line equation is y - 4 = 4(x - 2), which simplifies to y = 4x - 4, or 4x - y = 4.