\(2A=1+\frac{1}{2}+\frac{1}{2^2}+.......+\frac{1}{2^{99}}\)
\(\Rightarrow2A-A=\left(1+\frac{1}{2}+\frac{1}{2^2}+.......+\frac{1}{2^{99}}\right)-\left(\frac{1}{2}+\frac{1}{2^2}+\frac{1}{2^3}+.......+\frac{1}{2^{100}}\right)\)
\(A=1-\frac{1}{2^{100}}\)
\(A=\frac{2^{100}-1}{2^{100}}\)
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+\(\frac{1}{3}+\frac{1}{^{^{3^2}}}+\frac{1}{3^3}+...+\frac{1}{3^n}\)
Rut gon bieu thuc : 1 +\(\frac{1}{2}+\frac{1}{2^2}\)+\(\frac{1}{2^3}\)+.......+\(\frac{1}{2^{2012}}\)
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 \(A=\left(\frac{1}{2^2}-1\right).\left(\frac{1}{3^2}-1\right).\left(\frac{1}{4^2}-1\right)....\left(\frac{1}{100^2}-1\right)\)
rut gon bieu thuc sau:
a) 34^2+35^2+........+100^2
b)1^2+3^2+5^2+...+99^2
rut gon bieu thuc:(1/2+1)(1/3+1)(1/4+1).....(1/99+1)
