Question

tính\(\sqrt{3+\sqrt{5}}-\sqrt{3-\sqrt{5}}\)

Answer 1

Đặt phép tính bằng A A^2=6+4=10

Answer 2

     \(\sqrt{3+\sqrt{5}}-\sqrt{3-\sqrt{5}}\)

\(=\sqrt{\left(\sqrt{\frac{5}{2}}+\sqrt{\frac{1}{2}}\right)^2}-\sqrt{\left(\sqrt{\frac{5}{2}}-\sqrt{\frac{1}{2}}\right)^2}\)

\(=\left|\sqrt{\frac{5}{2}}+\sqrt{\frac{1}{2}}\right|-\left|\sqrt{\frac{5}{2}}-\sqrt{\frac{1}{2}}\right|\)

\(=\sqrt{\frac{5}{2}}+\sqrt{\frac{1}{2}}-\sqrt{\frac{5}{2}}+\sqrt{\frac{1}{2}}\)

\(=2.\sqrt{\frac{1}{2}}=\sqrt{2}\)

(Tíck cho mìk vs nhá!)

Answer 3

Nhầm √2 mới đúng