Method

Evaluating a Function

Evaluating a function involves determining the value of the function when its independent variable is set to a specific value. This is done by substituting the given input value for the variable and evaluating the function rule. As an example, consider the value of the following function when x=4. f(x)=3x+4 To evaluate a function for a particular input, there are two steps to follow.

Substitute the Input for x

Substitute the given input value for every instance of the independent variable in the function. In this case, 4 is substituted for x.

f(x)=3x+4

Substitute

x= 4

f( 4) = 3( 4)+4

Evaluate the Expression

Next, evaluate the resulting expression by performing the required operations. The simplified value will be the output for the given input value.

f(4) = 3(4)+4

Multiply

f(4) = 12 + 4

AddTerms

Add terms

f(4) = 16

As shown, when the input is 4, the output of the function is 16.

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