Question

solve on the interval [0,2pi)
2cos^2x-5cosx+2=0

Answer 1

i cant tell if i should be verifying or simplifying..?

Answer 2

you need to solve...means find values of x.
let cos x = y
then you get a quadratic equation, which u can sove ?

Answer 3

*solve

Answer 4

cosx=y? where does y come in?

Answer 5

It's not a quadratic, but you can treat it like one.

Let u=cox

Then 2u^2 - 5u + 2 = 0

Factor. Substitute back, and solve.

Answer 6

OHH okay that makes a lot more sense, ill try that out