Question

2cos(4x)−1=0

Answer 1

please help

Answer 2

\[2\cos(4x)-1=0\\
2\cos(4x)=1\\
\cos(4x)=\frac{1}{2}\\
4x=\arccos\left(\frac{1}{2}\right)+2\pi n, n\in \mathbb{z} \text{ since cosine is periodic over periods of } 2\pi \\
4x=\frac{\pi}{3}+2\pi n\\
x=\frac{\pi}{12}+\frac{\pi n}{2}=\frac{\pi+6\pi n}{12}, n\in\mathbb{Z}\]

Answer 3

you need help with all of those questions?

Answer 4

yess pleae

Answer 5

:'(

Answer 6

Atually I forgot one answer too

Answer 7

\(\arccos(1/2)=\frac{5\pi}{3}\) so add that answer (with multiples of 2pi\) aswell.. And as or the rest that is WAY too many questions

Answer 8

just for your information...