Please help with this question on functions?

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2 Answers
Apr 30, 2018

See below

Explanation:

The way I interpret the question is that you have the function
f(x)f(x), each with its own restricted domain.

Domain= the values xx is allowed to take in the function.

The question really states, when translated into words that:

**Given the function f(x),f(x), where if xx is greater than 4, the function of ff is equal to 3x-5. If instead xx is less than or equal to 4 then a function of xx is equal to x^2x2. **

Thus;

  1. If xx is greater than 4, apply f(x)=3x-5f(x)=3x5
    2.If xx is less than or equal to 4, apply f(x)=x^2f(x)=x2

Hence in 1.:

f(7)=3(7)-5=21-5=16f(7)=3(7)5=215=16

For 2.:
f(4)=4^2=16f(4)=42=16

As the equation states that f(x)=x^2f(x)=x2 applies if xx is less than OR equal to 44.

For 3.: 4>x4>x as x=-3x=3 so we must apply the first function.

f(-3)=(-3)^2=9f(3)=(3)2=9

Apr 30, 2018
  1. 16
  2. 16
  3. 9

Explanation:

f(7) =>f(7) substitute x=7 x=7 into 3x-5=21-5=16 3x5=215=16
because x>4x>4

f(4) =>f(4) substitute x=4x=4 into x^2=4^2=16x2=42=16
because x=4x=4

f(-3) =>f(3) substitute x=-3x=3 into x^2=(-3)^2=9x2=(3)2=9
because x<4x<4