# How do you calculate #cos(tan^-1 (-12 / 5))#?

##### 2 Answers

May 15, 2015

If you have a graphing calculator, you can simply punch in the equation.

I am using the TI-84 Plus with it in 'degree mode'

When I put in

The equation listed above I got the answer of .3846153846

Which would be rounded to .385 or .38 degrees.

May 15, 2015

A triangle with sides

Let us use

Then

So

and