# Different ways of writing the same answer? Trig Functions.?

I am taking an online Trig course in which we have to use MyMathLab (MML). I am doing my homework over finding the 6 different Trig functions. The questions I am currently working on look like this:

EXAMPLE: -5x +y = 0 , x > 0

When I go to put in the answers for sin, cos, ect. It sometimes says my answers are wrong but yet when I go to "Help me Solve This" my answers are correct they are just written in a different format. Yet, sometimes the very next question on my homework will have the answer in the "normal to me" way.

EXAMPLE: SIN =

ME: 5 / sqrt26

MML: 5sqrt26 / 26

I'm confused. Which way is it? And if MML is right (#2), why? I don't see how that makes sense or that it is simplified. Are their rules to which numbers must be in that format while other numbers can be in the way that makes sense to me?

Sorry if this is confusing but I'm not sure how to explain it without actually showing you the page.

### 1 Answer

- Barney KrebsLv 47 years agoFavorite Answer
The specific example you give reflects an old rule about presenting irrational numbers. Under this rule, irrational numbers should never appear in the denominator of a fraction, and you should rationalize the denominator to avoid this case. Here, note that MML's answer is Sqrt(26)/Sqrt(26) times your answer, which is the usual way to rationalize denominators.

I would suggest that you try rationalizing the denominator before reporting your answers and see how much this narrows the scope of your problem.

If you have other, distinct examples please repost this question.