\(A=\left(\dfrac{m+\sqrt{m^2-n^2}}{m-\sqrt{m^2-n^2}}-\dfrac{m-\sqrt{m^2-n^2}}{m+\sqrt{m^2-n^2}}\right):\dfrac{4m\sqrt{m^2-n^2}}{n^2}\)
\(=\left(\dfrac{\left(m+\sqrt{m^2-n^2}\right)^2-\left(m-\sqrt{m^2-n^2}\right)^2}{m^2-m^2+n^2}\right)\cdot\dfrac{n^2}{4m\sqrt{m^2-n^2}}\)
\(=\dfrac{m^2+2m\sqrt{m^2-n^2}+\left(m^2-n^2\right)-m^2+2m\sqrt{m^2-n^2}-\left(m^2-n^2\right)}{n^2}\cdot\dfrac{n^2}{4m\sqrt{m^2-n^2}}\)
\(=\dfrac{4m\sqrt{m^2-n^2}}{4m\sqrt{m^2-n^2}}\)
=1
Đúng 2
Bình luận (0)
