Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Easy precal question

  1. Oct 18, 2005 #1
    Can someone help me with a few simple problems:

    These 0's have lines through them, and are slanted. I used 0\ to represent that.

    1.) If sin0\ = 3/5 and 0\ is in quadrant II, find sin 2(0\). (Hint: sin 2(0\) = 2 sin 0\ cos 0\)?

    2.) The trigonometric expression, sin 0\(cot 0\ + tan 0\), is equilvalent to which of the following?
    (A) sec(0\)
    (B) sin(0\)
    (C) 1
    (D) sin^2(0\)
    (E) csc(0\)

    3.) The trigonometric expression, sin 0\ + cot 0\ cos 0\, is equivalent to which of the following?
    (A) sec 0\
    (B) csc 0\
    (C) 2 sin 0\
    (D) 1
    (E) cos^2(0\)

    Thanks for your help!
  2. jcsd
  3. Oct 18, 2005 #2
    I'm guessing that any "0's with slanted lines through them" would be the greek letter theta, which looks like this: [itex]\theta[/itex].

    Beyond that, I really cannot help you unless you show some work and show where you got stuck.

    I'm sure that your pre calc book contains all the necesary trig identites, and hopefully some example problems as well.
  4. Oct 18, 2005 #3


    User Avatar
    Science Advisor
    Homework Helper

    For 1, first derive what theta is, then calculate cos. For 2-3, use trig identities in your textbook or see the links here.
  5. Oct 18, 2005 #4
    If you are still stuck, for questions 2 and 3 the relevant trig identities are


Share this great discussion with others via Reddit, Google+, Twitter, or Facebook