# SIN, COS, TAN help?

by ArcherofScience
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 P: 35 Hello, I'm having some problems. So for geometry class today, the teacher taught us this COS, SIN, TAN stuff. I got the concept how to get the fractions from the triangle and everything. Problem is how to plug it in the calculator. I have a basic TI-30XA, and I'm trying to plug in fractions for the SIN, COS, and TAN, but I have no clue how to plug it in easily. For example the fraction : 16 over 34. How do I get the SIN of it? Its really urgent someone replies back. I have been trying all night, and I have a chemistry test tomorrow, so I can't spend all my time working on geometry just to plug in something in the calculator. Thanks, ArcherofScience
 PF Patron Sci Advisor Thanks Emeritus P: 15,671 Just calculate 16/34 with you calculator and then hit the SIN button.
P: 35
 Quote by micromass Just calculate 16/34 with you calculator and then hit the SIN button.

I tried it, it worked!! Thankyou thankyou thankyou soooo much. Your like the coolest person yet! I feel like a complete idiot not even realizing that it was this simple. Thankyou you saved my life tonight with Homework. Woohoo! :D.

thanks Micromass.

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## SIN, COS, TAN help?

Do be careful. Your calculator probably calculates the sine of an angle in degrees. You can check by putting in sin(90). If it outputs 1, then your calculator is set to degrees. This is ok if your geometry homework deals with degrees. But sometimes you need another thing called "radians". If you want to calculate the sine of something in radians then you should adjust your calculator.

If you don't know what a radian is, then just ignore this post.
P: 35
 Quote by micromass Do be careful. Your calculator probably calculates the sine of an angle in degrees. You can check by putting in sin(90). If it outputs 1, then your calculator is set to degrees. This is ok if your geometry homework deals with degrees. But sometimes you need another thing called "radians". If you want to calculate the sine of something in radians then you should adjust your calculator. If you don't know what a radian is, then just ignore this post.

I looked at my calculator and it says degree on top, so I guess i'm fine. :), thanks again btw.
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