CIE P1 Question

Test whether the given point lies on the straight line (or curve) with the given equation.

(p, (p-1)^2 + 1) on y = x^2 - 2x + 2

(p-1)^2 + 1 = p^2 - 2p + 2

p^2 + 1 + 1 = p^2 - 2p + 2

p^2 = p^2 - 2p

The point does not satisfy the equation.

Where am I going wrong? :confused:

Reply 1

BabyMaths

Original post by goodgrief

Test whether the given point lies on the straight line (or curve) with the given equation.

(p, (p-1)^2 + 1) on y = x^2 - 2x + 2

(p-1)^2 + 1 = p^2 - 2p + 2

p^2 + 1 + 1 = p^2 - 2p + 2

p^2 = p^2 - 2p

The point does not satisfy the equation.

Where am I going wrong? :confused:

(p,(p-1)^2+1)=(p,p^2-2p+2)

Edit: I see you had that. You have the answer in your second line. Not sure what you're doing after that.

Oh I see now. (p-1)^2 is not p^2+1. Multiply out (p-1)(p-1).