Question:
Find all values of z such that z^4 - 4z^2 +3 = 0.
What I did:
z^2 = y
y^2 - 4y + 3 = 0
(y - 3)(y - 1) = 0
y = 3 ... y2 = 3 ... y = rt 3
y = 1 ... y^2 = 1 ... y = 1
Why is my answer wrong?
Because z^4, your answers should read:
y = +or- sqrt(3), and
y = +or- 1
