
Trigonometry Trigonometry Math Forum 
 LinkBack  Thread Tools  Display Modes 
May 3rd, 2018, 03:49 AM  #1 
Newbie Joined: May 2018 From: UK Posts: 2 Thanks: 0  find the possible values of sin theta if cos theta = 2/3
Hello 1. Find the possible values of sin theta if: a. Cos theta = 2/3 b. cos theta =  3/sq13 Can someone explain the steps to take to find the values of the above? I have looked online and was not able to get a clear understanding what is needed to get the values which will help me with my exam next month. Thank you very much. 
May 3rd, 2018, 06:02 AM  #2 
Global Moderator Joined: Oct 2008 From: London, Ontario, Canada  The Forest City Posts: 7,912 Thanks: 1110 Math Focus: Elementary mathematics and beyond 
By Pythagoras, $\sin^2\theta+\cos^2\theta=1$, so a) $\sin\theta=\pm\sqrt{1\cos^2\theta}$. Use known values to complete the calculation. You can employ a similar method for b). 
May 3rd, 2018, 06:09 AM  #3 
Newbie Joined: May 2018 From: UK Posts: 2 Thanks: 0 
Thank you.


Tags 
2 or 3, cos, find, sin, theta, values 
Thread Tools  
Display Modes  

Similar Threads  
Thread  Thread Starter  Forum  Replies  Last Post 
How $3sin^3 \theta cos^3\theta$ obtained?  Ganesh Ujwal  Trigonometry  4  April 29th, 2018 06:08 AM 
Finding Two Values of Theta  System  Trigonometry  2  July 29th, 2015 08:34 AM 
$\int\limits_{\gamma} \frac{z}{(z1)(z2)}$, $\gamma(\theta) = re^{i\theta}$  SourPatchKid  Complex Analysis  0  April 21st, 2015 05:15 PM 
if sin(theta)= .1234 find (theta) in [4pi,pi]  mauro125  Algebra  3  February 22nd, 2014 05:57 PM 
How are these the first three positive values of theta? (Inv  Noraowolf  Algebra  2  June 14th, 2010 12:10 PM 