Calc
posted by Chelsea .
Find an expression for the function whose graph is the given curve.
The top half of the circle x^2 + (y2)^2 = 4
My final answer is y= 2 +/ sqrt of x4
However, I circled the positive sign because that's the top half. Is this right? I was not sure whether it was sqrt of x4 or sqrt of x^24

you are solving for y, so ...
(y2)^2 = 4  x^2
y  2 = ± √(4x^2)
since you want the top part
y = + √(4x^2) + 2
incidentally, √(4x^2) ≠ 2x
e.g. √(16  4) = √12 ≠ 42