Question

If f(n) = n2 - 2n, which of the following options are correct? Select all that apply. f(2) = 0 f(1) = 3 f(-4) = 24 f(5) = 35 f(-2) = 0

Answer 1

f(2)=0

f(-4)=24

Explanation:

We are given

f(n)=n^2-2n

We are asked which of the following are true?

f(2)=0

f(1)=3

f(-4)=24

f(5)=35

f(-2)=0

Let's start with f(2)=0.

f(2)=2^2-2(2)

f(2)=4-4

f(2)=0

So f(2)=0 is true.

Moving on to f(1)=3.

f(1)=1^2-2(1)

f(1)=1-2

f(1)=-1

So f(1)=3 is false.

Now for f(-4)=24.

f(-4)=(-4)^2-2(-4)

f(-4)=16+8

f(-4)=24

So f(-4)=24 is true.

f(5)=35?

f(5)=5^2-2(5)

f(5)=25-10

f(5)=15

So f(5)=35 is false.

Finally f(-2)=0.

f(-2)=(-2)^2-2(-2)

f(-2)=4+4

f(-2)=8

So f(-2)=0 is false.

Answer 2

The correct option are,

f(2) = 0, and f(-4) = 24

Explanation:

Given function,

`f(n) = n^2 - 2n`

By substituting n = 2,

`f(2) = 2^2 - 2(2) = 4 - 4 = 0`

By substituting n = 1,

`f(1) = 1^2 - 2(1) = 1 - 2 = -1`

By substituting n = -4,

`f(-4) = (-4)^2 - 2(-4) = 16 + 8 = 24`

By substituting n = 5,

`f(5) = (5)^2 - 2(5) = 25 - 10 = 15`

By substituting n = -2,

`f(-2) = (-2)^2 - 2(-2) = 4 + 4= 8`