>> Well lets talk about using the calculator and this will be no surprise to you. We just have to make sure the calculator is in radian mode. That's the most important thing. So if we're finding the sine of the real number 2, you see it corresponds to 2 radian and so all we have to do is select radian mode and enter into the calculator as we would expect. Sine 2, enter and the value is approximately 0.91 Notice a value between negative 1 and 1 within the range of values for the sine function. Now for cotangent and for secant and cosecant, the calculator doesn't actually have a button for those three functions but they're pretty easy to calculate because they are the reciprocals of either sine, cosine or tangent. So here's what we have to do, we just have to realize that now the cotangent of a real number is the reciprocal of the tangent of the same real number. So, on the calculator we find the tangent of that real number and to do that we enter tangent 2 pie divided by 3, close parenthesis. These parenthesis was automatically opened when you pressed tangent. Alright so you close the parenthesis. And now what you want to do is take the reciprocal of this all on the graphing calculators it is generally designated as X to the negative one. That means take the reciprocal of this, press enter, and boom. We have negative 0.58 approximately as the cotangent of that real number.