Answer :
To find [tex]\( f(3) \)[/tex] for the function [tex]\( f(x) = -5x^2 - x + 20 \)[/tex], follow these steps:
1. Substitute [tex]\( x = 3 \)[/tex] into the function:
The function is given as [tex]\( f(x) = -5x^2 - x + 20 \)[/tex]. Substitute [tex]\( x = 3 \)[/tex] into this function to find [tex]\( f(3) \)[/tex].
2. Calculate each term separately:
- First term: [tex]\( -5x^2 \)[/tex]
Replace [tex]\( x \)[/tex] with 3:
[tex]\[ -5(3)^2 = -5 \times 9 = -45 \][/tex]
- Second term: [tex]\( -x \)[/tex]
Again, replace [tex]\( x \)[/tex] with 3:
[tex]\[ -(3) = -3 \][/tex]
- Third term: The constant term is [tex]\( +20 \)[/tex].
3. Combine the results:
Add all the results together:
[tex]\[ -45 - 3 + 20 = -28 \][/tex]
Therefore, [tex]\( f(3) = -28 \)[/tex].
1. Substitute [tex]\( x = 3 \)[/tex] into the function:
The function is given as [tex]\( f(x) = -5x^2 - x + 20 \)[/tex]. Substitute [tex]\( x = 3 \)[/tex] into this function to find [tex]\( f(3) \)[/tex].
2. Calculate each term separately:
- First term: [tex]\( -5x^2 \)[/tex]
Replace [tex]\( x \)[/tex] with 3:
[tex]\[ -5(3)^2 = -5 \times 9 = -45 \][/tex]
- Second term: [tex]\( -x \)[/tex]
Again, replace [tex]\( x \)[/tex] with 3:
[tex]\[ -(3) = -3 \][/tex]
- Third term: The constant term is [tex]\( +20 \)[/tex].
3. Combine the results:
Add all the results together:
[tex]\[ -45 - 3 + 20 = -28 \][/tex]
Therefore, [tex]\( f(3) = -28 \)[/tex].
