The Math Forum

Ask Dr. Math - Questions and Answers from our Archives
Associated Topics || Dr. Math Home || Search Dr. Math

Trignometric Functions

Date: 5/31/96 at 20:47:8
From: Anonymous
Subject: Trignometric Functions

Hi!  I have to find the four missing trig functions. I've had a 
problem with the following two problems:

1. tan x = root3/3 and cos x = -root3/2

I set up a nice little right triangle, using the tangent and cosine, 
to find out the other functions, but the numbers weren't consistant, 
or something like that. I don't really know how to explain it, but it 
didn't work.

I had the same problem with the following:

2. sec x = root 2 and sin x = -root2/2

I appreciate any help!

Date: 6/2/96 at 17:18:40
From: Doctor Anthony
Subject: Re: Trignometric Functions

1) Cos(x) = -sqrt(3)/2 means the angle is in the third quadrant
   (= 180 + 30 = 210 degrees).  tan(x) = 1/sqrt(3) = sqrt(3)/3
   sin(x) = -1/2  cosec(x) = -2, cot(x) = sqrt(3), sec(x) = -2/sqrt(3)

2) sin(x)=-sqrt(2)/2 and a positive sec(x) means we are in the fourth 
   quadrant (= 360-45 = 315 degrees), cos(x)= 1/sqrt(2),  
   cosec(x) = -sqrt(2) tan(x) = -1,  cot(x) = -1 

-Doctor Anthony,  The Math Forum
 Check out our web site!   
Associated Topics:
High School Trigonometry

Search the Dr. Math Library:

Find items containing (put spaces between keywords):
Click only once for faster results:

[ Choose "whole words" when searching for a word like age.]

all keywords, in any order at least one, that exact phrase
parts of words whole words

Submit your own question to Dr. Math

[Privacy Policy] [Terms of Use]

Math Forum Home || Math Library || Quick Reference || Math Forum Search

Ask Dr. MathTM
© 1994- The Math Forum at NCTM. All rights reserved.