Evaluating Functions - Algebra

Evaluating Functions

Algebra

Goals:

• Determine output values given input values

• Determine input values given output values

Key Words

• Evaluate: to determine the value of something

• Function: a relation in which each element of the domain is mapped to (paired with) exactly one element of the range

• Input: the value that is transformed by a process and becomes an output

• Output: The result of an input that has been transformed by a process

Multiple Choice

 $f\left(2\right)=?$  

• -2

• -6

• -38

• 58

Finding an output value

•  $f\left(3\right)=?$  
  

•  $f\left(3\right)=\left(3\right)^4-3\left(3\right)^3+2\left(3\right)-1$  

•  $f\left(3\right)=81-3\left(27\right)+2\left(3\right)-1$  

•  $f\left(3\right)=81-81+6-1$  

•  $f\left(3\right)=5$  

Multiple Choice

 $f\left(1.5\right)=?$  

• 0

• 2

• 6

• -1

Determine the input of a function

•  $f\left(x\right)=\frac{1}{3}x-2$  

• Determine the input that would give an output value of -2/3

•  $-\frac{2}{3}=\frac{1}{3}x-2$  

•  $\left(\frac{6}{3}\right)+\left(-\frac{2}{3}\right)=\frac{1}{3}x-\left(\frac{6}{3}\right)+\left(\frac{6}{3}\right)$  

•  $\frac{4}{3}=\frac{1}{3}x$  

•  $3\times\frac{4}{3}=\frac{1}{3}x\times3$  

•  $x=4$  

Multiple Choice

 $f\left(x\right)=\frac{1}{4}x+3$  Determine the input value that would give an output value of  $\frac{14}{4}$  .

• 0

• 1

• 2

• 3

Poll

Rate your level of understanding

• 5- I've got this

• 4 - I am getting the hang of it

• 3 - Practice will help me fully understand

• 2- I have some questions

• 1 - I am lost

Multiple Choice

 $f\left(x\right)=\frac{1}{3}x+2$  

What is the inverse of the equation above?

•  $h\left(x\right)=\frac{1}{3}x-2$  

•  $h\left(x\right)=\frac{1}{3}x+2$  

•  $h\left(x\right)=3x-2$  

•  $h\left(x\right)=3x-6$