Answer
$y=\frac{1}{4}(x-2)^2+2$
Work Step by Step
Vertex: $(h,k)=(2,2)$
Standard form:
$y=a(x-h)^2+k$
$y=a(x-2)^2+2$
Now, use the point $(0,3)$ to find $a$:
$3=a(0-2)^2+2$
$3-2=a(4)$
$a=\frac{1}{4}$
$y=\frac{1}{4}(x-2)^2+2$