Let’s substitute x values of the minimum point of the graph into each equation and see which equation gives the correct equation ;
x = -3
y = 2
1. y = (x+3)^2-2
= (-3+3) ^2 -2
= 0^2 -2
= -2
Therefore first equation is wrong
2. y = (x-3)^2 -2
= (-3-3)^2 -2
y = 36-2
y = 34
Since y isn’t 34 the second equation is wrong
3. y = (x+3)^2 +2
= (-3+3)^2 +2
= 0^2 +2
= 2
Since y =2 the third equation is correct
Therefore third equation is correct