What Happens When a Function is Invoked with a Negative Argument?

[zak100]

Homework Statement

I am trying solve a question which invokes a function f(…) and the argument of function is the same function with -1 as an argument i.e.

f(f(-1))

However the statements of the function are not provided. Instead a graph is provided which is uploaded. I can't understand which variable of the graph i.e. x or y will get this value of -1?

Somebody please guide me?

Homework Equations

f(f(-1))

The Attempt at a Solution

I can't understand what would happen when function f(-1) is invoked. What statements would be executed? Which variable of the graph would get -1?Somebody please guide me.
Zulfi.

 

[Buffu]

Homework Statement

I am trying solve a question which invokes a function f(…) and the argument of function is the same function with -1 as an argument i.e.

f(f(-1))

However the statements of the function are not provided. Instead a graph is provided which is uploaded. I can't understand which variable of the graph i.e. x or y will get this value of -1?

Somebody please guide me?

Homework Equations

f(f(-1))

The Attempt at a Solution

I can't understand what would happen when function f(-1) is invoked. What statements would be executed? Which variable of the graph would get -1?

Find $f(-1)$.

Somebody please guide me.
Zulfi.

 

[SammyS]

Homework Statement

I am trying solve a question which invokes a function f(…) and the argument of function is the same function with -1 as an argument i.e.

f(f(-1))

However the statements of the function are not provided. Instead a graph is provided which is uploaded. I can't understand which variable of the graph i.e. x or y will get this value of -1?

Somebody please guide me?

Homework Equations

f(f(-1))

The Attempt at a Solution

I can't understand what would happen when function f(-1) is invoked. What statements would be executed? Which variable of the graph would get -1?

Somebody please guide me.
Zulfi.

Your figure:

I suppose the graph is to be interpreted as being y = ƒ(x) .

Is that how such graphs tend to be treated in your course/book ?

 

[mfb]

How do you simplify expressions like 5+(3*(4-1))? You start from the inside.
To evaluate f( f(-1) ), first find f(-1).

 

[Mark44]

However the statements of the function are not provided.

You don't need the function definition, since you have a graph of the function.

Follow the suggestion made by @Buffu.

 

[zak100]

Hi,
Thanks.

I suppose the graph is to be interpreted as being y = ƒ(x) .

Reference https://www.physicsforums.com/threads/function-without-statement.916696/

Based upon this rule:
y=f(-1)
Find the value of y for x=-1 from the graph
therefore y=2
Now f(f(-1)) = f(2)
Find the value of y for x=2 from the graph
therefore y= 1
Therefore answer of f(f(-1)) is 1.

This is correct.

Zulfi.

 

[Mark44]

y=f(-1)
Find the value of y for x=-1 from the graph
therefore y=2
Now f(f(-1)) = f(2)
Find the value of y for x=2 from the graph
therefore y= 1
Therefore f(f(-1)) is 1.

Your answer is correct, but you're writing a lot more than is necessary.
This is how I would do it.

From the graph, f(-1) = 2, and f(2) = 1,
so f(f(-1)) = f(2) = 1.​

 

[zak100]

Hi,
Thanks for improving my solution. God bless you.

Zulfi.