Posted by House on Friday, October 3, 2008 at 1:02pm.
If 0<theta<90 and tan theta= (square root 3)/2, find cos theta?
tan(t) =ã3 /2; cos(t) = 1/ã(1+(tant)^2)= 1/ã(1+3/4) = 2/ã7
right or wrong?

Math  Reiny, Friday, October 3, 2008 at 4:45pm
You are doing this the hard way.
make a diagram
since tan theta = √3/2, and tan theta = opposite/adjacent, make the oppose √3 and the adjacent 2
In your head you could do Pythagoras and get the hypotenuse √7
since cos theta = adjacent/hypotenuse
cos theta = 2/√7
which is what you got.
Answer This Question
Related Questions
 math  I have a question I have been working on since yesterday and I am not ...
 Maths complex numbers  Find tan(3 theta) in terms of tan theta Use the formula...
 Calculus  I wanted to confirm that I solved these problems correctly (we had to...
 Algebra II  Multiple Choice (theta) means the symbol 0 with the dash in it. 1.)...
 Trigonometry  Thank you STEVE!!!!! Suppose that Cos (theta) = 1/square root 2 ...
 Trigonometry  Prove the following identities: 1. (tan theta  sin theta)^2 + (1...
 Trigonometry  Prove the following identities: 1. (tan theta  sin theta)^2 + (1...
 Trig  1. Establish the identity: sin(theta+3pi/2)=cos(theta) 2. Find the exact...
 math  Another: theta is a second quadrant angle in standard position and tan ...
 math  There are no typos and no work b/c I don't know how to do them. Thanks. 1...
More Related Questions