I'm not getting the right answer and don't know why... SOLVE: cos(theta)=1/4

...so I take the inverse cos of each side so that I have theta=1.32. The first answer is 1.32+2kpi (and I get that), but second answer is 4.97+kpi and I don't know how they got that?

Question

I'm not getting the right answer and don't know why... SOLVE:  cos(theta)=1/4

...so I take the inverse cos of each side so that I have theta=1.32. The first answer is 1.32+2kpi (and I get that), but second answer is 4.97+kpi and I don't know how they got that?

compassionate · Answer

Hi,

This question should be asked in $ \large\bf The ~{\href{ /Mathematics }{Mathematics ~Section}}$

It all depends on what you're solving for. If it's Z, then you'll have: 
$$\Theta = 1.32\pm 2\pi n, 4.65 \pm 2\pi n$$

anonymous · Answer

Sorry I didn't realize I was in the wrong section
Z?

compassionate · Answer

Yes, you'll have a lot more luck asking in the mathematics section.

Also, you need to clarify. Are we solving for degrees, radius, simplification, x, theta, Z, cos?