When do I use the trigonometric functions with the -1 on the top right of them that looks like an exponent? I've forgotten what they're called and I've forgotten when they're used.

Question

dape · Answer

They are the inverse of the regular trigonometric functions, this means that for example
$$ \sin(\sin^{-1}(x))=x $$
and similarly for the other ones, they are used among other things for getting the angle when you know the ratio of the sides of a triangle. They are also called arcsin, arccos, arctan etc.

anonymous · Answer

So would I use the inverse if I didn't have the degree measure?

dape · Answer

Say you wanted to solve the equation $\sin(\theta)=0.5$, then you could use arcsin on both sides to get
$$ \arcsin(\sin(\theta))=\theta=\arcsin(0.5)=30^o $$

dape · Answer

Think of the inverses "cancelling" the other function.

anonymous · Answer

Oh, okay. I think I've got it now. Thank you for your help!