Functions - College Level Math

If

f(x) = (x-3)

and

g(x) = (2x + 4)

Evaluate:

(f + g) (2)

Answer : 7

The above two equations are examples of the use of the Algebra of functions.

A function is a relation that does not repeat any first coordinates.

The problem is asking the student to evaluate (f+g)(2). This is the same as saying take the sum of functions f(2) and g(2) respectively and evaluate the result.

The steps involved in solving this problem are as follows:

• Substitute the equation of f(x) for the (f) value of the function.
  
• Substitute the equation of g(x) for the (g) value of the function.
  
• Add the two equations.
  
• Take the function with respect to (2) Evaluate the answer.
  

Here is the algebraic solution for the problem.

f(2) = ( 2 - 3) = -1

g(2) = ( 2(2) + 4 ) = ( 4 + 4 ) = 8

(f + g) (2) = ( -1 + 8 ) = 7


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