Hey guys, I have a problem.
I have the following math problem
f(x)=y=-1/2*(x-1)2+7

You have to set y=0,and I was wondering if my solution is correct. If not, please tell me why(I am worried about the part with the negative root)
My solution:
y=0
0=-1/2*(x-1)2+7|-7
-7=-1/2*(x-1)2|/1/2
-14=(x-1)2|root
+-root14=x-1|+1
x1=4,742
x2=-2,742

thanks in advance