2(cos^2(x))-cos(x)-1=0?

callum-harrison_609a551c93b1d

solve for , (0,2pi)

Update:

Between 0 and 2pi , sorry.

mein-hoon-na

(2cosx + 1)(cos x- 1) = 0

cos x = -1/2 or 1

cox = -1/2 => 4pi/3 or 8pi/3

cos x -= 1 => 0 or 2pi ( no solution as Between 0 and 2pi )

tbt

simple

( 2 cos x + 1 ) ( cos x - 1) = 0

( 2 cos x + 1 ) = 0

cos x = - 0.5

x = 120 degree

( cos x - 1) = 0

cos x = 1

x = 0 degree

cos x = 1

frak1a12345

Use the quadratic formula.

a = 2

b = -1

c = -1

You will get the values of cos x. From there you have to figure out what x is.