- #1
krusty the clown
Solve 2cos^2(x)+cos(x)-1=0 In the interval where x is greater or equal to 0 and less than or equal to 2pi
Let cos(x)=y
2y^2+y-1=0 Factors to
(2y-1)(y+1)=0
so y=1/2 or y=-1
cos(x)=-1 so x=pi
cos(x)=1/2 Here is my question, I know it equals pi/3, but can it also equal 5pi/3 ?
If someone would let me know I would greatly appreciate it
Let cos(x)=y
2y^2+y-1=0 Factors to
(2y-1)(y+1)=0
so y=1/2 or y=-1
cos(x)=-1 so x=pi
cos(x)=1/2 Here is my question, I know it equals pi/3, but can it also equal 5pi/3 ?
If someone would let me know I would greatly appreciate it