Question

Evaulate u^2-4u+2 when u=-2

Answer 1

You can just replace
`u` with 2:

`2^2 - 4*2 + 2 = 4 - 8 + 2 = \boxed{-2}`

Alternatively, you can complete the square.

`u^2 - 4u + 2 = u^2 - 4u + 4 - 2 = (u-2)^2 - 2`

When
`u=2`, the quadratic term vanishes and we again get -2.