+0  
 
+1
111
3
avatar+224 

A cosine function has a period of (6π)/5, an amplitude of 5, and a vertical translation 6 units down. The function is not reflected over the x-axis. What is the equation for this cosine function? 

f(x)=  [   ] cos( [   ] x) [   ]   

 

Select and put answers into the appropriate spot of the equation. There should be 3 answers.

 

[ 3π / 5 ]     [ 6/5 ]     [ 5 ]    [ 5/3 ]     [ -6 ]     [ 6π / 5 ]     [ -5 ]     [ -6 ]     [ 3/5 ]     [ 5π / 3 ]

 

 

I got f(x)=  [ 5 ] cos( [ 6π / 5 ] x) [ -6 ]. The only thing that's really having me second guess myself is the period. When I graph the equation, I get 5/3 as the period. If someone could help me understand why or correct me, I'd appreciate that a lot. smiley

 Mar 24, 2020
 #1
avatar+111330 
+2

We  have  this form :

 

y = A cos (Bx)  +  C

 

A  = the amplitude  = 5

 

B =   2pi / period =      2pi  [ (6/5) pi ]  =  2 / (6/5)   =    2 (5/6)  =  10/6 =   5/3

 

C   = the vertical  shift   =   -6

 

 

cool cool cool

 Mar 24, 2020
 #2
avatar+224 
+2

Thank you so much! I appreciate the fast response! 

So, correct me if I'm wrong, but 2pi / period is always used to get B in the equation? 

 Mar 24, 2020
 #3
avatar+111330 
+1

Yep.....always true

 

B =  2pi  / period     

 

 

cool cool cool

CPhill  Mar 24, 2020

10 Online Users

avatar