Find the cot^-1(-1/2) if tan^-1(-2) is about -63 degrees. explain.

Question

dumbcow · Answer

could you clarify the expression please...is that inverse cotangent

anonymous · Answer

yes that is sorry I made a typo

dumbcow · Answer

what do you mean by "of" ?

anonymous · Answer

yes that is correct

dumbcow · Answer

oh ok , if

anonymous · Answer

i don't 
does it mean times?

dumbcow · Answer

you should write your question as:
Given tan^-1 (-2) = 63 degrees
Find cot^-1 (-1/2)

$$\tan(\theta) = \frac{y}{x} \rightarrow \cot (\theta) = \frac{x}{y}$$
thus
$$\tan^{-1} (\frac{y}{x}) = \cot^{-1} (\frac{x}{y}) $$
-1/2 is reciprocal of -2, therefore it is also equal to about -63 degrees

anonymous · Answer

goody eye!

anonymous · Answer

Oh okay that makes sense thank you! my teacher was also talking about restrictions too which I don't understand where they come in to this problem

dumbcow · Answer

well since you are using tan, theta can't be pi/2

anonymous · Answer

Okay so I would say there is a restiction at pi/2?