Posted by Janine on .
determine the amplitude and period of each function.
1) y = 3sin (2xpi/2)
2) y = 3sin2 (xpi/4)
3) y = 2cos (2x+pi)
4) y = 2cos2 (x+pi/2)

Math Trigonometry 
Reiny,
for y = a sin (kx) or y = a cos (kx)
the amplitude is a and the period is 2π/k
so for the first one, y = 3 sin (2x  π/2)
amplitude is 3 , period = 2π/2 = π
do the others the same way. 
Math Trigonometry 
drwls,
The amplitude is the coefficient in front of the trig term. Forget whether it is + or .
Let a be the number in front of the x.
a = 2 pi/P, so
P = 2 pi/a
For question 1), the amplitude is 3 and the period is pi