Question

Find a solution to 3cos(θ)=−0.862 in radians

Answer 1

$3cos(\theta) = -0.862$
$\frac{3cos(\theta)}{3} = \frac{-0.862}{3}$
$cos(\theta) = -\frac{431}{1500}$
$cos^{-1}[cos(\theta)] = cos^{-1}(-\frac{431}{1500})$
$\theta = 106.6983737\°$
$\theta = 1.86223792^{r}$