1. ## Trig Solutions

Find ALL solutions to cos(x) = 17/20 in the interval [, ].

How would you go about finding the solutions between this range? Cheers.

2. Originally Posted by Haris
Find ALL solutions to cos(x) = 17/20 in the interval [, ].

How would you go about finding the solutions between this range? Cheers.
since $\displaystyle \frac{17}{20} > 0$ , solutions will be in quads I and IV

$\displaystyle \arccos\left(\frac{17}{20}\right) - 2\pi$
$\displaystyle \arccos\left(\frac{17}{20}\right) - 4\pi$
$\displaystyle -\arccos\left(\frac{17}{20}\right) - 2\pi$
$\displaystyle -\arccos\left(\frac{17}{20}\right) - 4\pi$