Hey,
The way to solve this question would be first look at where the curve crosses the x axis at x=4. so i put x=2 in f(x^2) which would yield 4. So at x=2 the y coodinate is 0 as that was what it was for 4. now repeat for a couple of coodinates. e.g for x=9 the curve is approaching the horizontal symptote y= -3 so put in x=3 in y=f(x^2) to get 9 and so at x=3 draw the new curve approaching -3
i know it complex but thats the way i do them