how to get tangent to the power of -1

Use atan (press 2nd followed by atan).  atan is the same as tan^-1

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Alan, that is not fully correct. While atan is the same as "tan^-1()", that "-1" is not actually it's power: it's merely a common notation to mean the inverse function (So if you had "3" instead that would be saying the tangent function 3 times).

 

Instead, tan to the power of -1 is referred to as "cot()" or "cotangent".

 

In simpler terms:

Suggest: y = tan(x)

∴ tan^-1(y) = x

∴ y^-1 = cot(x)

What you say is correct Sir_Emo.  Never-the-less, this question (together with the corresponding ones of sin^-1 and cos^-1) occurs frequently, and usually refers to the arctan (arcsin, arccos).  Of course, there isn't enough information in the question as it stands to determine unequivocally which is meant here!

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