Question

2cos^4-3cos^2+1=0

Answer 1

This is an equation that can be reduced to a quadratic.

let cos^2(x) = u

then you have

2u^2 - 3u + 1= 0

this can be factorised

so you get

(2u - 1)(u - 1) = 0

so u = 1/2 or 1

then cos^2(x) = 1/2 or 1


now all you have to do is solve for x.
just solve

Answer 2

thanks!!!

Answer 3

Treat it like a quadratic, even though it's not:\[(2\cos ^{2}-1)(\cos ^{2}-1)=0\]

Answer 4

thanks got it!

Answer 5

glad to help

Answer 6

be careful as there will be 4 solutions, positive and negative

Answer 7

yes yes thanks !

Answer 8

2cos^4(-3)cos^21=0
False