Evaluate the following expression.
$-2^2$

• A. $-4$
• B. $4$
• C. $-1$
• D. $2$

Answer: (A)

Verified step by step guidance

1. Identify the base and the exponent in the given exponential expression. Since the problem involves negative bases, pay close attention to whether the base is enclosed in parentheses or not, as this affects the sign of the result.
2. Recall the rule that when a negative number is raised to an even exponent, the result is positive, and when raised to an odd exponent, the result is negative. This is because multiplying an even number of negative factors results in a positive product, while an odd number results in a negative product.
3. Rewrite the expression clearly, for example, if the expression is \((-a)^n\), keep the parentheses to indicate the negative base is raised to the power \(n\). If the expression is \(-a^n\), understand that only \(a\) is raised to the power \(n\), and then the negative sign is applied.
4. Calculate the absolute value of the base raised to the exponent, which means computing \(a^n\) without considering the sign. This step focuses on the magnitude of the number.
5. Apply the sign determined in step 2 to the result from step 4. If the exponent is even, the result is positive; if odd, the result is negative. This completes the evaluation of the exponential expression with a negative base.