Subject: Functions
Name: Tori Morris
Who is asking: Student
Level: Middle

Question:
Consider the function f(x)=x2-3. Which of the following are true?

  1. f(1)>f(0)
  2. f(2)>f(-3)
  3. f(2)=f(-2)
  4. f(-1)=f(3).
More than one answer can be true.

That is the question and if you could teach me how you do it, that would be nice because Finals are coming up next week

Hi Tori,

At times it is helpful to think of a fuction as a procedure that describes what to do with the input variable. For your function f the input variable is x and the procedure description,

f(x) = x2 - 3

says "square the input variable and then subtract three". Thus f(1) says "square the input variable, 1, and then subtract three". That is f(1) = 12 - 3 = 1 - 3 = -2. Likewise f(0) = 02 - 3 = 0 - 3 = -3. Since -2 is larger than -3 statement 1 is true.

Now find f(x) for the remaining values of x, for example f(-2) = (-2)2 - 3 = 4 - 3 = 1, and check to see which of statements 2, 3 and 4 are true.

Cheers,
Penny.

 

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