Inputting tan-1(-5/2) on a Calculator

[dankelly08]

how do you type in,

tan-1(-5/2) (or any negative number)

on the calculator?? or just work it out?

 

[CompuChip]

Are you talking about the (-5/2)? Most calculators have a separate key for that, which usually has something like "(-)" printed on it (a short dash in parentheses), rather than the normal (longer) minus sign "${}-{}$".

If you are referring to the -1: there should again be a separate key. On my TI calculator it is Second + Tan, just find where is says tan^-1, atan, arctan, or something like that. Note that you should consider "tan^-1" as a single function, it's not something like x^-1 = 1/x, for which you can write in general x^-n = 1/xⁿ. Instead, it is defined by tan^-1(tan(x)) = x.

 

[dankelly08]

Yeah I got it, thanks a lot! it was(+/-)

I spent a full hour trying to figure that out lol..