Question

F(x)= 10x-5
What is the value of f-1(-4) ?​

Answer 1

`(1)/(10)`

Step-by-step explanation:

f(x) = y (output)

y = 10x - 5

Switch variables.

Solve for y.

x = 10y - 5

x + 5 = 10y

x/10 + 1/2 = y

`f^(-1)(x)` = 1/10x + 1/2

Put x as -4.

1/10(-4) + 1/2

-4/10 + 1/2

-4/10 + 5/10

= 1/10

Answer 2

`f^(-1)(-4) = (1)/(10)`

Step-by-step explanation:

Firstly finding
`f^(-1)(x)`

So,

`f(x) = 10x-5`

Substitute
`y = f(x)`

`y = 10x-5`

Exchange the values of x and y

`x = 10y-5`

Solving for y

`x = 10y-5`

Adding 5 to both sides

`10y = x+5`

Dividing both sides by 10

`y = (x+5)/(10)`

Replace
`y = f^(-1)(x)`

`f^(-1)(x) = (x+5)/(10)`

For x = -4

`f^(-1)(-4) = (-4+5)/(10)`

`f^(-1)(-4) = (1)/(10)`