Find all solutions to the followin ginterval 2cos^2+3cos+1=0

Your equation can be factored to

... (cos +1)(2cos +1) = 0

The zero product rule tells you solutions will be

... cos = -1 . . . . . . angle = odd multiples of π

... cos = -1/2 . . . . angle = even multiples of π ± 2π/3

Together, these are {2π/3, π, 4π/3} +2kπ. You need to choose the solutions among these that are in your interval. [The interval is not given in your problem statement.]

step-by-step explanation:

is their an equation anywhere i can take a   look at it and see if i am right.

the correct answer is c

good luck love