Chương I - Căn bậc hai. Căn bậc ba
Các câu hỏi tương tự
S=\(\dfrac{1}{1\sqrt{2}+2\sqrt{2}}+\dfrac{1}{2\sqrt{3}+3\sqrt{2}}+\dfrac{1}{3\sqrt{4}+4\sqrt{3}}+....+\dfrac{1}{99\sqrt{100}+100\sqrt{99}}\)
Rút gọn
A = \(\dfrac{1}{2\sqrt{1}+1\sqrt{2}}+\dfrac{1}{3\sqrt{2}+2\sqrt{3}}+\dfrac{1}{4\sqrt{3}+3\sqrt{4}}+...+\dfrac{1}{100\sqrt{99}+99\sqrt{100}}\)
Cho \(A=\dfrac{\sqrt{2}-\sqrt{1}}{1+2}+\dfrac{\sqrt{3}-\sqrt{2}}{2+3}+...+\dfrac{\sqrt{100}-\sqrt{99}}{99+100}\). CMR \(A< \dfrac{1}{2}\)
Bài 1 : chứng minh. \(\dfrac{1}{\sqrt{1}}+\dfrac{1}{\sqrt{2}}+\dfrac{1}{\sqrt{3}}+...+\dfrac{1}{\sqrt{99}}+\dfrac{1}{\sqrt{100}}>10\)
\(\sqrt{1+\dfrac{1}{1^2}+\dfrac{1}{2^2}}+\sqrt{1+\dfrac{1}{2^2}+\dfrac{1}{3^2}}+...+\sqrt{1+\dfrac{1}{99^2}+\dfrac{1}{100^2}}\)
Tính giá trị biểu thức :
\(P=\sqrt{1+\dfrac{1}{2^2}+\dfrac{1}{3^3}}+\sqrt{1+\dfrac{1}{3^2}+\dfrac{1}{4^2}}+...+\sqrt{1+\dfrac{1}{99^2}+\dfrac{1}{100^2}}\)
Rút gọn:
a) \(A=\dfrac{1}{\sqrt{3}+\sqrt{5}}+\dfrac{1}{\sqrt{5}+\sqrt{7}}+\dfrac{1}{\sqrt{7}+\sqrt{9}}+... +\dfrac{1}{\sqrt{97}+\sqrt{99}}\)
b) \(B=\dfrac{1}{2\sqrt{1}+1\sqrt{2}}+\dfrac{1}{3\sqrt{2}+2\sqrt{3}}+...+\dfrac{1}{2006\sqrt{2005}+2005\sqrt{2006}}+\dfrac{1}{2007\sqrt{2006}+2006\sqrt{2007}}\)
Tính :
P = \(\dfrac{1}{1+\sqrt{2}}\) + \(\dfrac{1}{\sqrt{2}+\sqrt{3}}\) + \(\dfrac{1}{\sqrt{3}+\sqrt{4}}\) + ........ + \(\dfrac{1}{\sqrt{99}+\sqrt{100}}\)
Thanks trước nkoa mấy man 
dfrac{2sqrt{3}-3sqrt{2}}{sqrt{6}}-dfrac{2}{1-sqrt{3}}dfrac{4}{sqrt{6}+sqrt{2}}-dfrac{sqrt{54}+sqrt{2}}{sqrt{3}+1}dfrac{5+2sqrt{5}}{sqrt{5}}-dfrac{20}{5+sqrt{5}}-sqrt{20}Bài 2sqrt{25x^2-10x+1}sqrt{4x^2+8x+4}sqrt{x^2-3}+1xsqrt{7-2x}sqrt{x^2+7}sqrt{9x-27}+dfrac{1}{2}sqrt{4x-12}-9sqrt{dfrac{x-3}{9}}2
Đọc tiếp
\(\dfrac{2\sqrt{3}-3\sqrt{2}}{\sqrt{6}}-\dfrac{2}{1-\sqrt{3}}\)
\(\dfrac{4}{\sqrt{6}+\sqrt{2}}-\dfrac{\sqrt{54}+\sqrt{2}}{\sqrt{3}+1}\)
\(\dfrac{5+2\sqrt{5}}{\sqrt{5}}-\dfrac{20}{5+\sqrt{5}}-\sqrt{20}\)
Bài 2
\(\sqrt{25x^2-10x+1}=\sqrt{4x^2+8x+4}\)
\(\sqrt{x^2-3}+1=x\)
\(\sqrt{7-2x}=\sqrt{x^2+7}\)
\(\sqrt{9x-27}+\dfrac{1}{2}\sqrt{4x-12}-9\sqrt{\dfrac{x-3}{9}}=2\)