We want to identify whether the function:
[tex]y=-(x+3)^2+5[/tex]
opens up or down. For doing so, we will identify the sign of the letter to the power of 2, and with this in mind we will simplify the expression, thus,
[tex]\begin{gathered} y=-(x+3)^2+5 \\ =-(x^2+6x+9)+5 \\ =-x^2-6x-9+5 \\ =-x^2-6x-4 \end{gathered}[/tex]
As the sign of the value "a" is negative, this means that the function goes down.
