Question

can someone walk me through this problem?

Let f(x) = x2 - 8x + 5. Find f(-1).

Answer 1

f(-1) is just the value of the function f when x = -1.

Answer 2

Function f is called x^2 - 8x + 5.

Answer 3

What is the value of f when x = -1?

Answer 4

ok so i just plug x in and then solve?

Answer 5

yes

Answer 6

ok hold on please

Answer 7

so f = 11?

Answer 8

No.

Answer 9

ok ill try again

Answer 10

Let's see...when x = -1, you get

(-1)^2 -8(-1) + 5

1 + 8 + 5

= 14

Agree?

Answer 11

oh okay i see what happened i forgot the first x was to the second power

Answer 12

thank you

Answer 13

welcome.

Now you can find f(anything).

Answer 14

how would i solve with the f^-1? would i just turn the number into a negative number?
Let f(x) = 2x - 6 Solve f^-1(x) when x = 2.

Answer 15

@Easyaspi314 ?

Answer 16

f^(-1) is the inverse of function f.

Answer 17

To find the inverse of a function f, interchange x with y, and y with x, and then solve for y.

Answer 18

As an example:

What is the inverse of f(x) = 2x + 3?

ANSWER: We are given that y = 2x + 3

We interchange x with y and y with x, we get

x = 2y + 3

Now, we solve for y, we get

y = (x-3)/2

So we say that the inverse of f, f^(-1) = (x-3)/2.