How to Evaluate Functions Given Values of Independent Variables and Simplifying
- 1). Evaluate a function when given the independent variable by first using algebra to isolate the "y" variable on one side of the equation. Rewrite the "y" as "f(x)" and plug in the known independent variable for the "x" value in the expression. Simplify for the answer.
- 2). Evaluate the function 3y = 6x + 12 when x = 8. Divide both sides by 3 to isolate the variable: y = 2x + 4. Rewrite the "y" variable: f(x) = 2x + 4.
- 3). Plug in the known value for the variable: f(x) = 2(8) + 4. Simplify the expression to solve: f(x) = 16 + 4 = 20.