Tính :
\(\dfrac{1}{1+\sqrt{2}}+\dfrac{1}{\sqrt{2}+3}+.....+\dfrac{1}{\sqrt{2017}+2018}\)
Rút gọn
A=\(\sqrt{1^2+\dfrac{1}{2^2}+\dfrac{1}{3^2}}+\sqrt{1^2+\dfrac{1}{3^2}+\dfrac{1}{4^2}}+......+\sqrt{1^2+\dfrac{1}{2017^2}+\dfrac{1}{2018^2}}\)
HELP ME,PLS
\(\sqrt{1+2017^2+\dfrac{2017^2}{2018^2}}+\dfrac{2017}{2018}\)
\(\sqrt{1+2017^2+\dfrac{2017^2}{2018^2}}+\dfrac{2017}{2018}\)
cau a cho x,y,z\(\ne\)0 thoa man x+y+z=0. CM: \(\sqrt{\dfrac{1}{x^2}+\dfrac{1}{y^2}+\dfrac{1}{z^2}}=|\dfrac{1}{x}+\dfrac{1}{y}+\dfrac{1}{z}|\) cau b tinh G=\(\sqrt{1+\dfrac{1}{2^2}+\dfrac{1}{3^2}}+\sqrt{1+\dfrac{1}{3^2}+\dfrac{1}{4^2}}+\sqrt{1+\dfrac{1}{4^2}+\dfrac{1}{5^2}}+.....+\sqrt{1+\dfrac{1}{2017^2}+\dfrac{1}{2018^2}}\)
Tính M=\(\sqrt{1^2+2017+\dfrac{2017}{2018}}+\dfrac{2017}{2018}\)
Tính tổng:
\(S=\dfrac{1}{2\sqrt{1}+\sqrt{2}}+\dfrac{1}{3\sqrt{2}+2\sqrt{3}}+...+\dfrac{1}{2017\sqrt{2016}+2016\sqrt{2017}}\)
Tính giá trị của biểu thức \(P=\dfrac{4\left(x+1\right)x^{2018}-2x^{2017}+2x+1}{2x^2+3x}\) tại \(x=\sqrt{\dfrac{1}{2\sqrt{3}-2}-\dfrac{3}{2\sqrt{3}+2}}\)
Cho biểu thức B = \(\left(\dfrac{2\sqrt{x}+x}{x\sqrt{x}-1}-\dfrac{1}{\sqrt{x}-1}\right).\left(1-\dfrac{\sqrt{x}+2}{x+\sqrt{x}+1}\right)\)
( Với \(x\ge0\) và \(x\ne1\))
a) Rút gọn B
b) Tính \(\sqrt{B}\) với \(x=2018+2\sqrt{2017}+1\)