giải phương trình :\(\sqrt{x^2+1-2x}+\sqrt{x^2+4x+4}=\sqrt{1+2020^2+\frac{2020^2}{2021^2}}+\frac{2020}{2021}\)
M = \(\sqrt{1+2019^2+\frac{2019^2}{2020^2}}+\frac{2019}{2020}\)
N = \(\sqrt{1+\frac{1}{2^2}+\frac{1}{3^2}}+\sqrt{1+\frac{1}{3^2}+\frac{1}{4^2}}+...+\sqrt{1+\frac{1}{2019^2}+\frac{1}{2020^2}}\)
Cám ơn các cậu.
Ta có
\(P=\frac{\sqrt{2}}{\sqrt{2}+\sqrt{4}}+\frac{\sqrt{2}}{\sqrt{4}+\sqrt{6}}+...+\frac{\sqrt{2}}{\sqrt{2018}+\sqrt{2020}}\)
=>\(\frac{P}{\sqrt{2}}=\frac{\sqrt{4}-\sqrt{2}}{\left(\sqrt{4}-\sqrt{2}\right)\left(\sqrt{4}+\sqrt{2}\right)}+...+\frac{\sqrt{2020}-\sqrt{2018}}{\left(\sqrt{2020}-\sqrt{2018}\right)\left(\sqrt{2020}+\sqrt{2018}\right)}\)
=>\(\frac{P}{\sqrt{2}}=\frac{\sqrt{4}-\sqrt{2}}{2}+\frac{\sqrt{6}-\sqrt{4}}{2}+...+\frac{\sqrt{2020}-\sqrt{2018}}{2}\)
=> \(\frac{P}{\sqrt{2}}=\frac{\sqrt{2020}-\sqrt{2}}{2}\)
=> \(P=\sqrt{1010}-1\)
Vậy \(P=\sqrt{1010}-1\)
Tính \(S=\frac{1}{1\sqrt{2}+2\sqrt{1}}+\frac{1}{2\sqrt{3}+3\sqrt{2}}+...+\frac{1}{2020\sqrt{2021}+2021\sqrt{2020}}\)
Tính : \(\sqrt{1+2020^2+\frac{2020^2}{2021^2}}+\frac{2020}{2021}\)
a)Cho a,b thuộc N* và b=a+1
Thu gọn biểu thức:
\(P=\sqrt{1+a^2+\frac{a^2}{b^2}}+\frac{a}{b}\)
b)Áp dụng:Tính giá trị biểu thức:
\(P=\sqrt{1+2020^2+\frac{2020^2}{2021^2}}+\frac{2020}{2021}\)
c)Tính tổng:
\(Q=\sqrt{1+\frac{1}{1^2}+\frac{1}{2^2}}+\sqrt{1+\frac{1}{2^2}+\frac{1}{3^2}}+....+\sqrt{1+\frac{1}{2020^2}+\frac{1}{2021^2}}\)
Cho \(f\left(x\right)=\frac{x^3}{1-3x+3x^2}.\) Tính \(A=f\left(\frac{1}{2020}\right)+f\left(\frac{2}{2020}\right)+...+f\left(\frac{2018}{2020}\right)+f\left(\frac{2019}{2020}\right).\)
Cho \(f\left(x\right)=\frac{x^3}{1-3x+3x^2}.\) Tính \(A=f\left(\frac{1}{2020}\right)+f\left(\frac{2}{2020}\right)+...+f\left(\frac{2018}{2020}\right)+f\left(\frac{2019}{2020}\right).\)
\(\frac{\sqrt{x-2020}-1}{x-2020}+\frac{\sqrt{y-2020}-1}{y-2020}+\frac{\sqrt{z-2020}-1}{z-2020}=\frac{3}{4}\)