By Ajay Kumar

Verified by Ajay Kumar

Find the value of \(\sqrt{12+\sqrt{12+\sqrt{12+\cdots}}}\).

  1. 3

  2. 4

  3. 6

  4. 12

Answer: B

Solution

Let \(x=\sqrt{12+\sqrt{12+\sqrt{12+\cdots}}}\). Since the expression repeats indefinitely, \(x=\sqrt{12+x}\). Squaring gives \(x^2=12+x\), so \(x^2-x-12=0\). Factoring gives \((x-4)(x+3)=0\). Since a square root is non-negative, \(x=4\). Trick: Let the repeating radical equal \(x\) and solve the resulting quadratic equation.

Community answers

Votes use a first-party browser cookie to help prevent repeat votes. Votes indicate helpfulness, not correctness.

No community answers yet. Be the first to share how you solved it.

Share your solution

Help other learners understand the steps. Your answer will be reviewed before it appears.

Your answer will be checked by our team before publishing.