My Math Forum  

Go Back   My Math Forum > High School Math Forum > Trigonometry

Trigonometry Trigonometry Math Forum


Thanks Tree1Thanks
  • 1 Post By Joppy
Reply
 
LinkBack Thread Tools Display Modes
June 28th, 2017, 04:40 AM   #1
Newbie
 
Joined: Jun 2017
From: Serbia

Posts: 3
Thanks: 0

Find the domain

f(x)=sqrtsin(cosx)

Im very confused.
Guiless is offline  
 
June 28th, 2017, 05:26 AM   #2
Senior Member
 
Joined: Feb 2016
From: Australia

Posts: 1,322
Thanks: 453

Math Focus: Yet to find out.
Maybe elaborate on your confusion.
Thanks from 123qwerty
Joppy is offline  
June 28th, 2017, 06:01 AM   #3
Newbie
 
Joined: Jun 2017
From: Serbia

Posts: 3
Thanks: 0

Cosx needs to have positive value so sin(cosx) is greater or eqal to 0 ? But if cosx is for example 1/2, how can i find sin1/2 if thats not an angle but a number?

Last edited by Guiless; June 28th, 2017 at 06:04 AM.
Guiless is offline  
June 28th, 2017, 06:04 AM   #4
Senior Member
 
Joined: Dec 2012
From: Hong Kong

Posts: 853
Thanks: 311

Math Focus: Stochastic processes, statistical inference, data mining, computational linguistics
Quote:
Originally Posted by Guiless View Post
Cosx needs to have positive value so sin(cosx) is greater or eqal to 0 ? But if cosx is for example 1/2, how can i find sin1/2 if thats not an angle but a mumber?
Just treat the $\displaystyle \frac{1}{2}$ as if it were in radians.
123qwerty is offline  
June 28th, 2017, 06:41 AM   #5
Math Team
 
Joined: Jul 2011
From: Texas

Posts: 2,624
Thanks: 1305

$f(x) = \sqrt{\sin(\cos{x})}$

note $-1 \le \cos{x} \le 1 \implies \sin(\cos{x}) \ge 0$ for $0 \le \cos{x} \le 1$

$0 \le \cos{x} \le 1$ for values of $x$ in quadrants I and IV

$-\dfrac{\pi}{2} + 2k\pi \le x \le \dfrac{\pi}{2} + 2k\pi$, $k \in \mathbb{Z}$
skeeter is offline  
June 28th, 2017, 08:16 AM   #6
Newbie
 
Joined: Jun 2017
From: Serbia

Posts: 3
Thanks: 0

Thank you ive got it.
Guiless is offline  
Reply

  My Math Forum > High School Math Forum > Trigonometry

Tags
domain, find



Thread Tools
Display Modes


Similar Threads
Thread Thread Starter Forum Replies Last Post
How do I find the image set and domain? alexpasty Algebra 2 January 8th, 2014 05:51 AM
Find the Domain of the Function. Shamieh Algebra 4 April 30th, 2013 08:59 PM
How to find restricted domain alloy Algebra 4 October 30th, 2012 09:45 AM
Find Domain symmetry Algebra 6 June 5th, 2007 06:34 AM
Find the Domain of the Function. Shamieh Calculus 3 December 31st, 1969 04:00 PM





Copyright © 2017 My Math Forum. All rights reserved.