Difficulty: Easy
Correct Answer: that number.
Explanation:
Introduction / Context:
Basic exponent rules are fundamental in electronics, controls, and signal processing. They underpin scientific notation, frequency scaling, and power calculations.
Given Data / Assumptions:
Concept / Approach:
By definition of exponents and the identity element for multiplication, a^1 = a. This follows from the law a^m * a^n = a^(m+n). Setting m = 0 and n = 1 gives a^0 * a^1 = a^(0+1) = a^1. Since a^0 = 1, we have 1 * a^1 = a, so a^1 = a.
Step-by-Step Solution:
Start from a^m * a^n = a^(m+n).Let m = 0, n = 1: a^0 * a^1 = a^1.Because a^0 = 1, the left side reduces to 1 * a^1.Therefore, a^1 = a (the original number).
Verification / Alternative check:
Test with examples: 10^1 = 10; 2^1 = 2; (-3)^1 = -3. The identity holds universally for real numbers.
Why Other Options Are Wrong:
Zero (option A) would imply all numbers equal zero when exponent is 1, which is false.
One (option B) corresponds to a^0, not a^1.
Two (option C) is arbitrary and incorrect.
Reciprocal (option E) corresponds to a^(-1), not a^1.
Common Pitfalls:
Mixing up a^0 = 1 and a^1 = a; keeping the exponent rules straight avoids algebra errors in engineering derivations.
Final Answer:
that number.
Discussion & Comments