# Function without statement

1. Jun 5, 2017

### zak100

1. The problem statement, all variables and given/known data
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 cant understand which variable of the graph i.e. x or y will get this value of -1?

2. Relevant equations
f(f(-1))

3. The attempt at a solution
I cant understand what would happen when function f(-1) is invoked. What statements would be executed? Which variable of the graph would get -1?

Zulfi.

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2. Jun 5, 2017

### Buffu

Find $f(-1)$.

Last edited by a moderator: Jun 5, 2017
3. Jun 5, 2017

### SammyS

Staff Emeritus

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 ?

4. Jun 5, 2017

### Staff: Mentor

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

5. Jun 5, 2017

### Staff: Mentor

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

6. Jun 6, 2017

### zak100

Hi,
Thanks.
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.

7. Jun 6, 2017

### Staff: Mentor

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.​

8. Jun 6, 2017

### zak100

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

Zulfi.