Carcass wrote:
What is the value of \(\frac{2}{2- \sqrt{2}}\)?
(A) 1
(B) 2
(C) 1 + √2
(D) 2 + √2
(E) 4
APPROACH #1: Use conjugate
Given:
2/
(2 - √2)Our goal is to rationalize ("fix") the denominator so that it doesn't have a root.
We'll do this by multiplying the numerator and denominator by the
conjugate of
2 - √2, which is
2 + √2Numerator:
2(
2 + √2) = 4 + 2√2
Denominator:
(2 - √2)(
2 + √2) = 4 - 2 = 2
So,
2/
(2 - √2) = (4 + 2√2)/2 = 2 + √2
Answer: DAPPROACH #2: Use calculator
Evaluate \(\frac{2}{2- \sqrt{2}}\) to get 3.414
Then evaluate each answer choice until you get 3.414
Answer: D