Question

y = -(x+5)^2 + 9 into standard form.

Answer 1

The given function is

$y=-(x+5)^2+9$

To express the function into standard form, expand the bracket

This gives

$\begin{gathered} y=-(x+5)(x+5)+9 \\ y=-(x^2+5x+5x+25)+9 \\ y=-(x^2+10x+25)+9 \end{gathered}$

Multiply the bracket with the minus sign

This gives

$y=-x^2-10x-25+9$

This further gives

$y=-x^2-10x-16$

Therefore, the equation in standard form is

$y=-x^2-10x-16$