1. Not finding help here? Sign up for a free 30min tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Trig identities (I think?) for precalc review

  1. Sep 22, 2016 #1
    1. The problem statement, all variables and given/known data
    My calc class is having me review precalc(which i'm really rusty on...)

    21. Find sin θ, sec θ, and cot θ if tan θ = 27
    22. Find sin θ, cos θ, and sec θ if cot θ = 4.
    23. Find cos 2θ if sin θ = 15
    24. Find sin 2θ and cos 2θ if tan θ = √2
    25. Find cos θ and tan θ if sin θ = 0.4 and π/2 ≤ θ < π.
    26. Find cos θ and sin θ if tan θ = 4 and π ≤ θ < 3π/2.


    2. Relevant equations


    3. The attempt at a solution
    I'm not going to ask you to do these for me, but since it's been several years since I've done any of this stuff(that i really do hate!) please refer me to videos / tutorials on how to work with them. My textbook only goes through one problem and that's it. The explanations are not the greatest as well.

    Thanks alot. I apologize for not giving an attempt but all my attempts are so horribly off it's not even worth showing.
     
  2. jcsd
  3. Sep 22, 2016 #2

    Math_QED

    User Avatar
    Homework Helper

    Do show your attempts.
     
  4. Sep 22, 2016 #3

    Mark44

    Staff: Mentor

    This one makes no sense. ##-1 \le \sin \theta \le 1##.
     
  5. Sep 26, 2016 #4
    It was meant to be sinx = 1/5. I've solved all the original question, they were a bit easier than I had imagined.

    Should I still post the solutions or can I mark this question as solved and move on?
     
  6. Sep 26, 2016 #5

    SammyS

    User Avatar
    Staff Emeritus
    Science Advisor
    Homework Helper
    Gold Member

    Probably either is fine. See what others say.

    Was #21 supposed to have 2/7 rather than 27?
     
  7. Sep 29, 2016 #6
    Yeah, it was 2/7. Not sure why they turned the way they did when I had copy pasted them
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Trig identities (I think?) for precalc review
Loading...