Expert: Sherman D. - 1/21/2005

Question
What is the equation of y=x^2 + 4 after:
(a)a dilation of 2
(b)a rotation of 180 degrees
(c)a rotation of 270 degrees  
(d)a reflection of y=3
I'm taking a big test next friday called the New York State regent and have to know this type of information.

Answer
this is all i can tell you.

b.) y = x^2 + 4 becomes y = -x^2 + 4, which keeps the graph at (0,4) and making it a 180 degrees rotation.

as for the rest, i either haven't done it or can't remember how to do it.

a.) Can't remember if we ever did dilation. It maybe
y = 4x^2 + 4
y = (1/4)x^2 + 4
y = 2x^2 + 8
y = (1/2)x^2 + 2

c.) I have no idea if we ever went to anything dealing with 270°. I could probably tell you how to rotate it 90°, -90°, and 180°

d.) I remember doing reflection along the x-axis and the y-axis, but as for reflection of y = 3, the answer might be
y = sqrt(x) + 3 but i am not certain.

I'm pretty good a expansions(stretching), shrinking, and shifting left, right, up, and down. As for rotations, dialations, and reflections, not certain.