Find the normal to the curve y = x^2 at x = 5.

Differentiate the original equation (y = x^2) to find the gradient (m) of the line which is a tangent to the curve.

Dy/dx = 2x 

Therefore m = 2

Calculate the negative reciprocal (m2) which will give the gradient of the normal.

m2 = -0.5

Using the equation y=mx+c find the equation of the normal.

When x=5, y=25.

25=(-0.5)(5) + c

c=27.5

y=-0.5x+27.5