Given the quadratic function below:
[tex] \large{f(x)= - {x}^{2} - 4x - 19}[/tex]
To find f(-9), simply substitute x = -9 in the function.
[tex] \large{f( - 9) = - {( - 9)}^{2} - 4( - 9) - 19} \\ \large{f( - 9) = - 81 + 36 - 19} \\ \large{f( - 9) = - 100 + 36 \longrightarrow \large \boxed { \purple{f( - 9) = - 64}}}[/tex]
Answer
Let me know if you have any doubts regarding the function.
