# Trigonomic Functions (Check My Solution)

• Apr 9th 2008, 01:34 AM
wickwiki
Trigonomic Functions (Check My Solution)
1. Find the amplitude, period, and phase shift of the function.

$y=3cos(2x+pi)$

What I think it should be:
amplitude=3
period= $pi$
phase shift=2

2. Write the equation of sine that has the given characteristics:
amplitude=3
period= $pi/2$
phase shift=2

What I think it should be:
$y=3sin[3(x-2)]$
• Apr 9th 2008, 04:16 AM
Mathstud28
You tell me if you are right
Quote:

Originally Posted by wickwiki
1. Find the amplitude, period, and phase shift of the function.

$y=3cos(2x+pi)$

What I think it should be:
amplitude=3
period= $pi$
phase shift=2

2. Write the equation of sine that has the given characteristics:
amplitude=3
period= $pi/2$
phase shift=2

What I think it should be:
$y=3sin[3(x-2)]$

in the equation $y=acos(bx+c)$....the amplitude is $|a|$...the period is $\frac{2\pi}{|b|}$ and the phase shift is $\frac{-c}{b}$...so are you right?
• Apr 9th 2008, 08:51 AM
wickwiki
1.

http://www.mathhelpforum.com/math-he...dbd345c3-1.gif
So, this would be:
amplitude=3
period= $2pi/2$
phase shift= $-pi/2$

2. Write the equation of sine that has the given characteristics:
amplitude=3
period=http://www.mathhelpforum.com/math-he...d2dddf53-1.gif
phase shift=2

What I think it should be:
• Apr 9th 2008, 02:58 PM
Mathstud28
Ok but look
Quote:

Originally Posted by wickwiki
1.

http://www.mathhelpforum.com/math-he...dbd345c3-1.gif
So, this would be:
amplitude=3
period= $2pi/2$
phase shift= $-pi/2$

2. Write the equation of sine that has the given characteristics:
amplitude=3
period=http://www.mathhelpforum.com/math-he...d2dddf53-1.gif
phase shift=2

What I think it should be:
if $3sin(3x-6)$ was the answer...using the method I gave you...the amplitude is $|3|$...check...the period $\frac{2\pi}{|3|}$.. =(....and its phase shift $\frac{-(-6)}{3}=2$...=)...try $3sin(4x-8)$