Question

Find the general solution of
cos 3x=-1/2​

Answer 1

Answer:

x=3×1/2

×=1/6

please write on copy

Answer 2

$The \: general \: solution \: of expression \: is x=\frac{2n\pi\pm 120}{3}$

Step-by-step explanation:

Given : Expression $\cos 3x=-\frac{1}{2}$

To find : The general solution of expression ?

Solution :

$\cos 3x=-\frac{1}{2}$

The expression is also written as,

$\cos 3x=\cos 120^\circ$

The general solution of $\cos \theta=\cos \alpha$ where, $\alpha\in [0,\pi]$

$\theta=2n\pi\pm \alpha$

So, the solution is

$3x=2n\pi\pm 120$

$x=\frac{2n\pi\pm 120}{3}$

The general solution of expression is $x=\frac{2n\pi\pm 120}{3}$