Question

consider the equation: 2cos(4x) +1 = 0 find all degree solutions Help please

Answer 1

2cos(4x)=-1
cos4x=-1/2
4x=c0s^-1(-1/2)

Answer 2

x=cos^-1(-1/2)/4

Answer 3

^^ what he said

now what is arccos of -1/2 ?
use unit circle

Answer 4

cos inverse

Answer 5

I get confused when it comes to the unit circle

Answer 6

\[x=(\cos ^{-1}(-1/2))/4\]

Answer 7

x=-(cos1/2)/4
have u got it now

Answer 8

Yes thanks :)

Answer 9

\[x = \frac{\pi}{6}, \frac{\pi}{3}\]

Answer 10

can you explain how you got that