Các câu hỏi tương tự
23 tháng 9 2021 lúc 20:50
Tính \(S=\sqrt{1+\dfrac{8.1^2-1}{1^2.3^2}}+\sqrt{1+\dfrac{8.2^2-1}{3^2.5^2}}+...+\sqrt{1+\dfrac{8.n^2-1}{\left(2n-1\right)^2.\left(2n+1\right)^2}}\)
Với\(n\in N\)
Tính
a) \(\dfrac{1}{3\sqrt{2}-2\sqrt{3}}-\dfrac{1}{2\sqrt{3}+3\sqrt{2}}\)
b) \(\dfrac{4\sqrt{3}-8}{2\sqrt{3}-4}-\dfrac{1}{\sqrt{5}-2}\)
\(\left(\dfrac{1}{2}\sqrt{\dfrac{1}{2}}-\dfrac{3}{2}\sqrt{4,5}+\dfrac{2}{5}\sqrt{50}\right):\dfrac{4}{15}\sqrt{\dfrac{1}{8}}\) tính
Thực hiện phép tính ( rút gọn biểu thức ) a) dfrac{sqrt{2}}{2sqrt{2}-3}+dfrac{1}{3+2sqrt{2}} b) dfrac{1}{sqrt{10}+sqrt{6}}+dfrac{1}{sqrt{6}-sqrt{10}}c) dfrac{-2}{3sqrt{8}}+dfrac{1}{3-2sqrt{2}}
Đọc tiếp
Thực hiện phép tính ( rút gọn biểu thức )
a) \(\dfrac{\sqrt{2}}{2\sqrt{2}-3}\)+\(\dfrac{1}{3+2\sqrt{2}}\) b) \(\dfrac{1}{\sqrt{10}+\sqrt{6}}\)+\(\dfrac{1}{\sqrt{6}-\sqrt{10}}\)
c) \(\dfrac{-2}{3\sqrt{8}}\)+\(\dfrac{1}{3-2\sqrt{2}}\)
Bài 1:Rút gọ các biểu thức sau
a)16\(\sqrt{\dfrac{1}{2}}-3\sqrt{8}-2\left(\sqrt{2}-1\right)^2\)
b)\(\dfrac{1}{2-\sqrt{3}}+\dfrac{\sqrt{2}^2+\sqrt{2}}{1+\sqrt{2}}-\sqrt{\left(\sqrt{2}-\sqrt{3}\right)^2}\)
c)\(\sqrt[3]{-27}+\sqrt{2}.\sqrt{8}\)
d)\(\dfrac{\sin25^0}{\cos65^0}+sin^235^0-\left(2023-\cos^235^0\right)\)
tính
a) \(\left(\dfrac{2\sqrt{3}-\sqrt{6}}{\sqrt{8}-\sqrt{2}}+1\right)\dfrac{1}{2+\sqrt{6}}\)
b) \(\sqrt{27}-6\sqrt{\dfrac{1}{3}}+\dfrac{\sqrt{3}-3}{\sqrt{3}}\)
1) thực hiện phép tính
a) \(2\sqrt{\dfrac{16}{3}}-3\sqrt{\dfrac{1}{27}}-6\sqrt{\dfrac{4}{75}}\)
b) \(\left(6\sqrt{\dfrac{8}{9}}-5\sqrt{\dfrac{32}{25}}+14\sqrt{\dfrac{18}{49}}\right).\sqrt{\dfrac{1}{2}}\)
c) \(\sqrt{\left(\sqrt{2}-2\right)^2}-\sqrt{6+4\sqrt{2}}\)
giúp mk vs ạ mk đang cần gấp
Tính tổng:
\(S=\dfrac{1}{2\sqrt{1}+1\sqrt{2}}+\dfrac{1}{3\sqrt{2}+2\sqrt{3}}+\dfrac{1}{4\sqrt{3}+3\sqrt{4}}+...+\dfrac{1}{121\sqrt{120}+120\sqrt{121}}\)
7) (\(\sqrt{\dfrac{3}{2}}\) - \(\sqrt{\dfrac{2}{3}}\)) : \(\dfrac{1}{\sqrt{6}}\)
8) ( 1+ \(\sqrt{2}\) + \(\sqrt{3}\) ) ( 1 + \(\sqrt{2}\) - \(\sqrt{3}\) )
Chứng minh đẳng thức
\(\left(4-\sqrt{7}\right)^2=23-8\sqrt{7}\)
\(\sqrt{9-4\sqrt{5}}-\sqrt{5}=-2\)
\(\dfrac{\sqrt{4-2\sqrt{3}}}{1+\sqrt{2}}:\dfrac{\sqrt{2}-1}{\sqrt{3}+1}=2\)
\(\left(\dfrac{2\sqrt{3}-\sqrt{6}}{\sqrt{8}-2}-\dfrac{\sqrt{216}}{3}\right).\dfrac{1}{\sqrt{6}}=-1,5\)