Decoding f(3): A Simple Step-by-Step Evaluation of f(x) = 3 βˆ’ 3Β²/2

Understanding how to evaluate mathematical expressions is a foundational skill in algebra and beyond. Today, we break down a specific function: f(3) = 3 βˆ’ 3²⁄2, and walk through every step to arrive at the final answer of βˆ’1.5. This process not only clarifies a single problem but also strengthens key algebraic reasoning skills.


Understanding the Context

Breaking Down the Expression f(3) = 3 βˆ’ 3²⁄2

At first glance, the expression
f(3) = 3 βˆ’ 3²⁄2
may look complex due to the combination of constant, exponentiation, and rational division. However, by following standard order-of-operations rules (PEMDAS/BODMAS), we simplify it step by step.


Step 1: Exponentiation β€” Evaluate 3Β²

Key Insights

In algebra, the symbol 3Β² means 3 squared, which equals 3 Γ— 3 = 9.
So,
3Β² = 9

Now substitute back:
f(3) = 3 βˆ’ 9⁄2


Step 2: Division β€” Evaluate 9⁄2

The expression now contains a division: 9 ⁄ 2.
This is a proper fraction, representing 9 divided by 2, which equals 4.5 in decimal form.
So,
9⁄2 = 4.5

Final Thoughts

Now the function becomes:
f(3) = 3 βˆ’ 4.5


Step 3: Subtraction β€” Final Computation

Subtracting a larger number from a smaller one gives a negative result:
3 βˆ’ 4.5 = βˆ’1.5

Thus,
f(3) = βˆ’1.5


Why Understanding f(3) Matters

While this function is simple, mastering such evaluations builds confidence in handling linear, quadratic, and rational expressions. Functions like f(x) form the backbone of higher mathematicsβ€”from calculus to computer science.

Understanding each operation’s place in the calculation chain helps prevent errors, especially when solving equations, analyzing graphs, or optimizing real-world problems.