Posted by Crystal on Tuesday, December 11, 2012 at 7:47pm.
For f(x) = 1/2sin2(x90°)
What are the transformations?
The 1/2 means a vertical compression by a factor of 1/2
And (x90°) means there's a phase shift right 90°
But what does the 2 mean? The one immediately left to the (x90°).
Does it mean a horizontal compression by factor of 1/2?
Because when I draw the graph for it going by what I have above, I get something different from what I calculate the main 5 points as :
(x,y) > (2x+90°, 1/2y)
(0,0) > (90°, 0)
(90,1)> (270, 1/2) ... When I draw the graph, the point I get is (270, 0).

Math  Reiny, Tuesday, December 11, 2012 at 9:01pm
The 2 in
f(x) = (1/2) sin 2(x90°) affects the frequency
for sin k(....), the period of the sine curve is 360°/k
or we can say that there are k complete curves from 0 to 360
So the 2 causes a compression factor of 2 of the standard sine curve.
that is, for f(x) = (1/2) sin (x90°) there would be ONE complete sine curve from 0 to 360 , while for
f(x) = (1/2) sin 2(x90°) there will be TWO complete sine curves from 0 to 360
So, let's say we pick x = 30·
we have
f(30°) = (1/2) sin 2(3090°)
= (1/2) sin 2(60°)
= (1/2) sin (120°)
= (1/2)(√3/2) = √3/4 or appr .433
etc