You are here:

Advanced Math/Trigonometric functions

Advertisement

Expert: - 8/27/2009


Question
what are the six trigonometric functions of an angle used for? Sine, cosine, tangent, cotangent, secant, and cosecant.

and also,
use the trigonometric function values of quadrantal angles given in this section to evaluate each expression. an expression such as cot^2 90(degrees) means (cot 90[degrees])^2, which is equal to 0^2=0

cos 90(degrees) + 3 sin 270(degrees)

the answer my calculator gave me was -3 but i have no idea how to figure the problem out without a calculator

Answer

SineCosine
Questioner: dillon
Country: United States
Category: Advanced Math
Private: No
Subject: trig
Question: what are the six trigonometric functions of an angle used for? Sine, cosine, tangent, cotangent, secant, and cosecant.

>> For that you must ask your teacher. This site has a 65000-character limit on answers.

and also,
use the trigonometric function values of quadrantal angles given in this section

>> what section?

to evaluate each expression. an expression such as cot^2 90(degrees) means (cot 90[degrees])^2, which is equal to 0^2=0

cos 90(degrees) + 3 sin 270(degrees)

the answer my calculator gave me was -3 but i have no idea how to figure the problem out without a calculator

>> I suggest that you memorize (ugly word, but...) the graphs of sine (black) and cosine (red).  Then keep in mind that  pi = 180, pi/2 = 90, 3pi/2 = 270.  Then you will just know the values:

cos 90 = 0,  sin 270 = -1.

Paul Klarreich

Expertise

I can answer questions in basic to advanced algebra (theory of equations, complex numbers), precalculus (functions, graphs, exponential, logarithmic, and trigonometric functions and identities), basic probability, and finite mathematics, including mathematical induction. I can also try (but not guarantee) to answer questions on Abstract Algebra -- groups, rings, etc. and Analysis -- sequences, limits, continuity. I won't understand specialized engineering or business jargon.

Experience

I taught at a two-year college for 25 years, including all subjects from algebra to third-semester calculus.

Education/Credentials
-----------

©2012 About.com, a part of The New York Times Company. All rights reserved.