Hello,

I shall post the problem with the answer (s) as a given, but it's more of an explanation on what's just happened from which I'm after.

Anyway:

$\displaystyle -540 < 3x < 540 $

$\displaystyle tan\ 3x = -1 \Rightarrow 3x = -405, -225, -45, 135, 315, 495 $

$\displaystyle x = -135, -75 , -15, 45, 105, 165 $

I'm confused how we compute these angles in a problem like this. It's when the coefficient of x is >1 and the range is bigger than $\displaystyle 360^{\circ} $

If I was given a problem like this:

$\displaystyle 0 < x < 360^{\circ} $

$\displaystyle tan\ x = (1) $

For all positive angles - I would have no problem.

I would be grateful for an explanation on what's going on when it's like the preceding case at the beginning of the thread.

Thank you for your attention.