Question 931952:  What is the amplitude, period and phase shift of the following function: 
 
y=1+COS (3x + pi/2) 
 
How would I graph one complete period?  
 Answer by lwsshak3(11628)      (Show Source): 
You can  put this solution on YOUR website! What is the amplitude, period and phase shift of the following function: 
y=1+COS (3x + pi/2) 
How would I graph one complete period? 
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Equation for cos function: y=Acos(Bx-C), A=amplitude, period=2π/B, Phase shift=C/B. 
For given cos function: 
A=1 
B=3 
Period=2π/B=2π/3 
1/4 period=(2π/3)/4=2π/12=π/6 
C=π/2 
Phase shift:C/B=(π/2)/3=π/6 (to the left) 
.. 
Determine coordinates: 
set up inequality of cos function for one period 
0 ≤ (3x+π/2) ≤ 2π/3 
subtract π/2 from each term 
-π/2 ≤ 3x ≤ π/6= 
divide each term by 3 
-π/6 ≤ x ≤ π/2 
.. 
coordinates of graph: 
(-π/6,2),(0,1),(π/6,0),(2π/6,1),(3π/6,2) 
or 
(-π/6,2),(0,1),(π/6,0),(π/3,1),(π/2,2) 
 
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