Question

Thực hiện các phép tính :

1. \(A=\sqrt{2-\sqrt{3}}\sqrt{2+\sqrt{2-\sqrt{3}}}\sqrt{2+\sqrt{2+\sqrt{2-\sqrt{3}}}}\sqrt{2+\sqrt{2+\sqrt{2+\sqrt{2-\sqrt{3}}}}}\)

2. \(B=\left(\dfrac{1}{1+\sqrt{2}}+\dfrac{2}{2+\sqrt{3}}+...+\dfrac{1}{20+\sqrt{21}}\right)\cdot2022\)

Giải chi tiết giúp mình ạ 

Answer 1

1:

\(A=\sqrt{2-\sqrt{3}}\cdot\sqrt{2+\sqrt{2-\sqrt{3}}}\cdot\sqrt{2^2-\left(2+\sqrt{2-\sqrt{3}}\right)}\)

\(=\sqrt{2-\sqrt{3}}\cdot\sqrt{2+\sqrt{2-\sqrt{3}}}\cdot\sqrt{2-\sqrt{2-\sqrt{3}}}\)

\(=\sqrt{2-\sqrt{3}}\cdot\sqrt{4-2+\sqrt{3}}\)

\(=\sqrt{2-\sqrt{3}}\cdot\sqrt{2+\sqrt{3}}=1\)

Answer 2