Find the value of sqrt(20 + sqrt(20 + sqrt(20 + … infinity))).
A4
B5
C6
D10
Explanation
x = sqrt(20 + x) => x^2 – x – 20 = 0 => (x – 5)(x + 4) = 0 => x = 5.
Exam Relevance
- Topic: Algebra
- Subtopic: Infinite Series
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