Calculator features?

Question

I just purchased Texas InstrumentTI-30XIIS Scientific Advanced 2-line calculator for college. What website can i go to,to learn what some of the features(keys)mean. SIN,COS,TAN, etc..... Please help!!

Answer 1

I gather you didn't take trigonometry in school. :)

SIN, COS, TAN are abbreviations for the trigonometric functions Sine, Cosine, and Tangent.  (there's also Secant, Cosecant, and Cotangent).

They relate to angles... so you'd talk about "the sine of an angle of 45 degrees".  Specifically, they represent the ratio of the different sides of a right triangle where one of the angles is the given angle..

Wikipedia has an explanation here...

http://en.wikipedia.org/wiki/Trigonometr...

There's another good explanation here...

http://www.geocities.com/mathfair2002/sc...

As to how you'd use it...  if you had to solve an equation like...

X = cosine (45 degrees)

... you'd press COS and 45 and = and your calculator should give you the answer : 0.707106781

(your calculator might give you a different answer... 0.525321989.  If it does that, it means your calculator is set to expect angles in "radians" instead of "degrees".  There's probably a switch on your calculator so that you can change the Sine, Cosine, Tangent calculator to use degrees or radians, whichever you need at the moment.)

Hope this helps!