🧩 The Challenge

Opening challenge — read aloud

"Here's an expression: \(\sqrt{3+2\sqrt2}\). Can your group find its exact value — no calculator, no decimals? You already have every skill you need to do this. You just don't know it yet."

1
Phase 1
Run It Forward
Task 1a

Expand \((1+\sqrt2)^2\), \((2+\sqrt3)^2\), \((\sqrt2+\sqrt3)^2\).

Task 1b

Compare each result to its starting pair \((m,n)\). What connects them?

Task 1c

Conjecture: \((\sqrt m+\sqrt n)^2 = \) ___ \(+2\sqrt{\text{___}}\)

2
Phase 2
Run It Backward
The reverse problem

Find \(m,n\) so that \((\sqrt m+\sqrt n)^2 = 5+2\sqrt6\).

Task 2a

Write two equations linking \(m,n\) to 5 and 6.

Task 2b & 2c

Solve for \(m,n\), then write \(\sqrt{5+2\sqrt6}\) as \(\sqrt m+\sqrt n\).

3
Phase 3
The General Method
Task 3a

Try \(\sqrt{7+4\sqrt3}\). Rewrite \(4\sqrt3\) as \(2\sqrt{\text{something}}\) first.

Task 3b & 3c

Apply the method, then simplify — check if a surd reduces further.

Task 3d

Write the general method for denesting \(\sqrt{a+c\sqrt b}\).

4
Phase 4
The Infinite Nest
Task 4a & 4b

For \(x=\sqrt{1+\sqrt{1+\sqrt{1+\cdots}}}\), explain why \(x=\sqrt{1+x}\), then form a quadratic.

Task 4c & 4d

Solve with the quadratic formula. Name the number you get.

🚀 Challenge

Replace every 1 with a 2 — what does the nest converge to now?