High School

Which of these is the standard form of the following function?

\[ f(x) = -9(x + 5)^2 + 4 \]

A. \[ f(x) = 9x^2 - 90x - 221 \]
B. \[ f(x) = -9x^2 - 90x - 221 \]
C. \[ f(x) = 9x^2 - 180x + 221 \]
D. \[ f(x) = -9x^2 - 180x - 221 \]

Answer :

Answer:

Hope this helps!

Step-by-step explanation:

Answer:

We conclude that the standard form of the given function is:

[tex]f(x)=-9x^2-90x-221[/tex]

Hence, option B is correct.

Step-by-step explanation:

We know that the standard form of the quadratic function is of the form

[tex]f\left(x\right)\:=\:ax^2\:+\:bx\:+\:c[/tex]

Given the function

[tex]f(x)=-9\left(x\:+\:5\right)^2\:+\:4[/tex]

as (x+5)² = x² + 10x + 25

[tex]f(x)=-9\left(x^2+10x+25\right)+4[/tex]

Expanding -9(x² + 10x + 25) = -9x² - 90x - 225

[tex]f\left(x\right)\:=-9x^2-90x-225+4[/tex]

simplifying

[tex]f(x)=-9x^2-90x-221[/tex]

Therefore, we conclude that the standard form of the given function is:

[tex]f(x)=-9x^2-90x-221[/tex]

Hence, option B is correct.