when graphed, which equation will yield the same maximum value as the graph of y=3x^2+6x+9

y=-3(x-1)^2-12
y=-3(x+1)^2-12
y=3(x-1)^2-12
y=3(x+1)^2+12

Question

when graphed, which equation will yield the same maximum value as the graph of y=3x^2+6x+9

y=-3(x-1)^2-12
y=-3(x+1)^2-12
y=3(x-1)^2-12
y=3(x+1)^2+12

irishboy123 · Answer

so this is an exercise in completing the square 

strikes me that the mental arithmetic will be simplified by noting that $y=3x^2+6x+9 \implies \dfrac{y}{3} = x^2 + 2x + 3$  and working ot from there :-)  

much easier to square things etc

BUT then putting the 3 back on the RHS so you can compare against your list

and then you see the problem!!  is there a typo in there??

airabell · Answer

thanks i got it from here. :)