Question

Find the exact solutions to each equation for the interval 0<=x<2pi. 2cos^2 x-3 cos x+1=0

Answer 1

hey yotis the question before they missed a solution

Answer 2

let u=cosx
2u^2-3u+1=0
2u^2-2u-u+1=0
2u(u-1)-(u-1)=0
(u-1)(2u-1)=0
u=1
u=1/2
but remember u=cosx
cosx=1 so x=0,2pi
cosx=1/2 so x=pi/3, 5pi/3

Answer 3

so theirs four solutions to this one?

Answer 4

we don't include 2pi if x<2pi

Answer 5

we include 2p if x<=2pi

Answer 6

so its just 0, pi/3 and 5pi/3 ?

Answer 7

yes! :)

Answer 8

alright, thanks.

Answer 9

haha that pic is pretty gay ill admit it but yeah i linked it to my facebook.

Answer 10

oh i was going to say u guys look cute (dont worry im not a guy)

Answer 11

haha thanks

Answer 12

lol