Đặt \(A=1+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{2012}}\)
\(\Rightarrow2A=2+1+\frac{1}{2}+\frac{1}{2^2}+...+\frac{1}{2^{2011}}\)
\(A=1+\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{2011}}+\frac{1}{2^{2012}}\)
\(\Rightarrow2A-A=A=2-\frac{1}{2^{2012}}\)
Rut gon bieu thuc sau
A=\(\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{100}}\)
Rut gon bieu thuc: S = \(\frac{1}{^{2^1}}+\frac{1}{2^2}+\frac{1}{2^3}+...+\frac{1}{2^{100}}\)
rut gon bieu thuc sau
a . S=1+\(\frac{1}{3}+\frac{1}{^{^{3^2}}}+\frac{1}{3^3}+...+\frac{1}{3^n}\)
cho bieu thuc A =\(\frac{a^3+2a^2-1}{a^3+2a^2+2a+1}\)
a)rut gon bieu thuc
b)chung minh rang neu a la so nguyen thi gia tri cua bieu thuc tim duoc o cau a la mot phan so toi gian
\(A=\frac{a^3+2a^2-1}{a^3+2a^2+2a+1}\)
a/ Rut gon bieu thuc
b/ Chung minh rang neu a la so nguyen thi gia tri cua bieu thuc tim duoc o cau a, la mot phan so toi gian
\(A=\frac{a^3+2a^2-1}{a^3+2a^2+2a+1}\)
a)rut gon bieu thuc
b)chung minh rang neu a la so nguyen thi gia tri cua bieu thuc tim duoc cua cau a la mot phan so toi gian
Rut gon bieu thuc: A=1+ 1/2+ 1/22+ 1/23+ ... +1/22012
GIUP MINH NHANH NHE
Rut gon \(A=\left(\frac{1}{2^2}-1\right).\left(\frac{1}{3^2}-1\right).\left(\frac{1}{4^2}-1\right)....\left(\frac{1}{100^2}-1\right)\)
rut gon bieu thuc:(1/2+1)(1/3+1)(1/4+1).....(1/99+1)
