Answer:
1. f(3) = 11
2. f( 1 ) = 6
3. f(-2) = -5
Explanation:
Note: I will only work on questions 1 and 2 in order to allow you to practice the techniques provided in this post, as you work on question 3. However, I will provide the correct answer for question 3, as your reference.
In order to evaluate each of the given functions, simply substitute the inputs provided in the function notation, f(x).
1. f(x) = 2x + 5, find f(3).
To evaluate the given linear function, simply substitute x = 3 as an input into the function:
f(3) = 2x + 5
f(3) = 2(3) + 5
f(3) = 6 + 5
f(3) = 11
Therefore, the value of f(x) = 2x + 5 given f(3) is: f(3) = 11.
2. f(x) = x² + 2x + 3, find f(1)
Similar to question 1, substitute x = 1 as the input of the given quadratic function.
f(x) = x² + 2x + 3
f( 1 ) = ( 1 )² + 2( 1 ) + 3
f( 1 ) = 1 + 2 + 3
f( 1 ) = 6
Therefore, the value of f(x) = x² + 2x + 3 given f( 1 ) is f( 1 ) = 6.
3. f(x) = 3x² + 5x - 7, find f (-2)
If evaluated properly, the correct answer is: f(-2) = -5.