Why do i get the wrong answer when using the inverse tan when using the computer I get it correct, What am I doing wrong?

convert by pushing the a/b/c button

You can see on the images below graphs of the function y=tan x and y=arc tan x and calculations for your problem


y=tan x





y=arc tan x

well there is no cot function on this calculator so you have to use the identity. Cot is 1/tan so the inverse cot is 1/inverse tan which is on this calculator so = 1/arctan(-4)

The trigonometric function [SIN],[COS] and [TAN] have inverse functions arc-sine, arc-cosine, and arc-tangent which are also implemented on scientific calculators. To access the inverse trigonometric functions you use the sequences [SHIFT][SIN], [SHIFT][COS] and [SHIFT][TAN]. The functions are marked on the body of the calculator as [SIN^-1], [COS^-1] and [TAN^-1].
When you use these functions, make sure that the angle unit is correctly set (as required by the problem you are solving) because the angle values returned are in the same unit as the one set.

The inverse tan, or arctan in excel is
=ATAN(A1)

Change A1 to number or cell you want the inverse tan of

The inverse trigonometric function share each the same physical key with its direct function. The inverse trigonometric functions are accessed with the [SHIFT] key
[SHIFT] [SIN] accesses the arcsine
[SHIFT][COS] accesses the arccosine
and [SHIFT][TAN] the arctangent.

Hello,
That habit of TI, Casio, and Sharp to label the inverse trigonometric functions with the -1 superscript can cause confusions.

1. The inverse trigonometric functions arcosine, arcsine, and arctangent (labeled by manufacturers as cos^-1, sin^-1, and tan^-1) should not be confused with the other trigonometric functions known as secant(x) =1/cos(x), cosecant(x)=1/sin(x) and cotangent(x) = 1/tan(x).
2. To avoid errors in the use of the inverse trigonometric functions, one must be careful and set the angle unit to the one required by the problem at hand (degrees, or radians)
3. To make the trigonometric functions really functions, their range is restricted.
4. In this calculator arcosine (x) gives results between 0 and 180 degrees (if angle MODE is Degree) or between 0 and Pi radians (if angle MODE is Radian).
5. The range of results for arcsine(x) and arctangent(x) is between -90 degrees and +90 degrees (if angle MODE Degree) or -Pi/2 and Pi/2 (if angle MODE is Radian)
   

With this information you should be able to set the angle unit correctly ([MODE][Radian] or [MODE][Degree] ) and interpret the results. If you want to extend the angle to other values, use the periodicity of the trigonometric functions.

Hope it helps

Hello,
The inverse tangent or arctangent shares the ame key as tan. You access it by pressing [2nd][tan] number [)] [ENTER]. Be warned! The angle value displayed is the same as the one set in [MODE].
Hope it helps

because cotangent, cosecant, and secant are all inverse trig functions, just type in 1 / |shift| trig function and the number if you are finding the angles. It might not be a dedicated button, but its an extra push, and it will give you the same result. *note that I put the shift press only because that is how you get the inverse tan to get an angle from a tan ratio.*

There is an inverse button below the math button, but if you hit second and the tan it should give you the inverse of tan. Hope this is what you wanted