Đáp án+Giải thích các bước giải:
`C=\sqrt{2+\sqrt{3}}-\sqrt{2-\sqrt{3}}`
`C=\sqrt{\frac{4+2\sqrt{3}}{2}}-\sqrt{\frac{4-2\sqrt{3}}{2}}`
`C=\sqrt{\frac{3+2\sqrt{3}+1}{2}}-\sqrt{\frac{3-2\sqrt{3}+1}{2}}`
`C=\sqrt{\frac{(\sqrt{3}+1)^2}{2}}-\sqrt{\frac{(\sqrt{3}-1)^2}{2}}`
`C=\frac{|\sqrt{3}+1|}{\sqrt{2}}-\frac{|\sqrt{3}-1|}{\sqrt{2}}`
`C=\frac{\sqrt{3}+1-\sqrt{3}+1}{\sqrt{2}}`
`C=\frac{2}{\sqrt{2}}`
`C=\sqrt{2}`
