IDNLearn.com is the perfect place to get answers, share knowledge, and learn new things. Ask your questions and get detailed, reliable answers from our community of knowledgeable experts.

Which function has zeros at [tex]$x = 10$[/tex] and [tex]$x = 2$[/tex]?

A. [tex]f(x) = x^2 - 12x + 20[/tex]

B. [tex]f(x) = x^2 - 20x + 12[/tex]

C. [tex]f(x) = 5x^2 + 40x + 60[/tex]

D. [tex]f(x) = 5x^2 + 60x + 100[/tex]


Sagot :

To determine which function has zeros at [tex]\( x = 10 \)[/tex] and [tex]\( x = 2 \)[/tex], we need to check each given function step-by-step and see if these values satisfy the conditions for being zero.

### Step-by-Step Solution:

1. Function 1: [tex]\( f(x) = x^2 - 12x + 20 \)[/tex]
- To find out if [tex]\( x = 10 \)[/tex] is a zero:
[tex]\[ f(10) = 10^2 - 12 \cdot 10 + 20 = 100 - 120 + 20 = 0 \][/tex]
So, [tex]\( x = 10 \)[/tex] is a zero of [tex]\( f(x) \)[/tex].
- To find out if [tex]\( x = 2 \)[/tex] is a zero:
[tex]\[ f(2) = 2^2 - 12 \cdot 2 + 20 = 4 - 24 + 20 = 0 \][/tex]
So, [tex]\( x = 2 \)[/tex] is also a zero of [tex]\( f(x) \)[/tex].

Thus, the function [tex]\( f(x) = x^2 - 12x + 20 \)[/tex] has zeros at [tex]\( x = 10 \)[/tex] and [tex]\( x = 2 \)[/tex].

2. Function 2: [tex]\( f(x) = x^2 - 20x + 12 \)[/tex]
- To find out if [tex]\( x = 10 \)[/tex] is a zero:
[tex]\[ f(10) = 10^2 - 20 \cdot 10 + 12 = 100 - 200 + 12 = -88 \][/tex]
Since [tex]\( f(10) \ne 0 \)[/tex], [tex]\( x = 10 \)[/tex] is not a zero of [tex]\( f(x) \)[/tex].

3. Function 3: [tex]\( f(x) = 5x^2 + 40x + 60 \)[/tex]
- To find out if [tex]\( x = 10 \)[/tex] is a zero:
[tex]\[ f(10) = 5 \cdot 10^2 + 40 \cdot 10 + 60 = 500 + 400 + 60 = 960 \][/tex]
Since [tex]\( f(10) \ne 0 \)[/tex], [tex]\( x = 10 \)[/tex] is not a zero of [tex]\( f(x) \)[/tex].

4. Function 4: [tex]\( f(x) = 5x^2 + 60x + 100 \)[/tex]
- To find out if [tex]\( x = 10 \)[/tex] is a zero:
[tex]\[ f(10) = 5 \cdot 10^2 + 60 \cdot 10 + 100 = 500 + 600 + 100 = 1200 \][/tex]
Since [tex]\( f(10) \ne 0 \)[/tex], [tex]\( x = 10 \)[/tex] is not a zero of [tex]\( f(x) \)[/tex].

After checking all the functions, only [tex]\( f(x) = x^2 - 12x + 20 \)[/tex] has zeros at [tex]\( x = 10 \)[/tex] and [tex]\( x = 2 \)[/tex].

Therefore, the function that has zeros at [tex]\( x=10 \)[/tex] and [tex]\( x=2 \)[/tex] is:
[tex]\[ f(x) = x^2 - 12x + 20 \][/tex]