NEeD MATH HeLP?

Question

For the following questions use the function : f(x) = x^2 - 13x + 40

1. Find f(0).
A. 40
B. 28
C. 32
D. 16

2. Solve f(x) =0
A.{-5,8}
B.{5,8}
C.{6,8}
D.{6,-8}

Answer 1

y = x² - 13x + 40
use formula:
[- b ± √(b² - 4ac)] / 2a

[1(-13)±√{-13}² - 4(1)(40)] / 2(1)
(13±√9)/ 2
x = 8 or 5.

y = x² - 13x + 40
y = (0)² - 13(0) + 40
y = 40.

Answer 2

1. f(0) means replace 'x' with 0.
f(0) = 0^2 - 13*0 + 40
f(0) = 40

2. Solve f(x) = 0
Solve x^2 - 13x + 40 = 0
(x - 5) * (x - 8) = 0
x = {5,8}

Answer 3

f(x) = x^2 - 13x + 40

Optionally, we can factor this.

f(x) = (x - 5)(x - 8)

This is actually a good idea because we then have to do less operations this way.

1. Find f(0).

f(0) = (0 - 5)(0 - 8) = (-5)(-8) = 40

2. Solve f(x) = 0

Again, factoring helps, because

f(x) = (x - 5)(x - 8)

Equating this to 0, we get

(x - 5)(x - 8) = 0

Which means x = {5, 8}

Answer 4

Problem 1
F(0) = 0^2+13*0+40 = 40
Answer = A

Problem 2
the function becomes 0 if you use the values +5 or +8 for x.
Answer = B
Please select as best answer if you are happy with it.
Cheers

Answer 5

For #1 just simply replace X with the number 0 then do the math.

For #2 you need to use the quadratic equation and then do the math.

These are not hard questions you just need to do the work.

Answer 6

f(0)=40
Answer is A
f(x)=0, x=(-13 +- Sqrt(13^2-4 * 40) / 2 = (13+- 3)/2 = 8 and 5
Answer is (B)

Answer 7

1. Answer A
2. x² - 13x + 40 = 0
d = -13² - 4.1.40
d = 169 - 160
d = 9

x = 13 +/- \/9) : 2
x' = (13 + 3) : 2 = 8
x" = (13 - 3) : 2 = 5
Answer is B.
:==:

Answer 8

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