Difficulty: Easy
Correct Answer: (3 + 2√2)
Explanation:
Introduction / Context:
Rationalizing denominators with surds is a classic skill. Using conjugates eliminates radicals in the denominator and yields a clean exact expression.
Given Data / Assumptions:
Concept / Approach:
Multiply numerator and denominator by the conjugate to create a difference of squares in the denominator.
Step-by-Step Solution:
Verification / Alternative check:
Numerical check: 3 + 2√2 ≈ 3 + 2*1.414 = 5.828; 1/(3 − 2*1.414) ≈ 1/(0.172) ≈ 5.814 (difference due to rounding of √2); exact values match symbolically.
Why Other Options Are Wrong:
Common Pitfalls:
Forgetting that (a − b)(a + b) = a^2 − b^2 and mis-squaring 2√2.
Final Answer:
(3 + 2√2)
Discussion & Comments