So sánh
\(\left(\frac{1}{2}\right)^{200};\left(\frac{1}{3}\right)^{200}\)
So sánh \(A=\left(1-\frac{1}{2^2}\right).\left(1-\frac{1}{3^2}\right).\left(1-\frac{1}{4^2}\right)...\left(1-\frac{1}{200^2}\right)\)với \(\frac{1}{2}\)
so sánh \(A=\frac{201+200}{201-200},B=\frac{\left(201^2+200^2\right)}{201^2-200^2}\)
So sánh
\(\left(\frac{-1}{8}\right)^{100}\)và \(\left(\frac{-1}{4}\right)^{200}\)
Ta có:
\(\left(\frac{-1}{8}\right)^{100}=\frac{\left(-1\right)^{100}}{8^{100}}=\frac{1}{\left(2^3\right)^{100}}=\frac{1}{2^{300}}\)
\(\left(\frac{-1}{4}\right)^{200}=\frac{\left(-1\right)^{200}}{4^{200}}=\frac{1}{\left(2^2\right)^{100}}=\frac{1}{2^{200}}\)
Vì \(2^{300}>2^{200}\)\(\Rightarrow\frac{1}{2^{300}}< \frac{1}{2^{200}}\)
\(\Rightarrow\left(\frac{-1}{8}\right)^{^{100}}< \left(\frac{-1}{4}\right)^{200}\)
So sánh: \(\left(-\frac{1}{8}\right)^{180}\) và \(\left(-\frac{1}{4}\right)^{200}\)
ta có:\(\left(-\frac{1}{8}\right)^{180}=\left(\frac{1}{8}\right)^{180}=\left(\frac{1}{4}\right)^{2^{180}}=\left(\frac{1}{4}\right)^{360}\)
ta có :\(\left(-\frac{1}{4}\right)^{200}=\left(\frac{1}{4}\right)^{200}\)
=>(1/4)^360<(1/4)^200
Vậy : (-1/8)^180 < ( -1/4)^200
Ta có: \(\left(\frac{-1}{8}\right)^{180}=\frac{-1^{180}}{8^{180}}=\frac{1}{8^{180}}\)
\(\left(\frac{-1}{4}\right)^{200}=\frac{-1^{200}}{4^{200}}=\frac{1}{4^{200}}\)
Suy ra để so sánh \(\left(\frac{-1}{8}\right)^{180}\)và\(\left(\frac{-1}{4}\right)^{200}\)thì ta chỉ cần so sánh 8180 và 4200
Ta có: 8180=(23)180=23.180=2540
4200=(22)200=22.200=2400
Ta thấy 2=2 nhưng 540>400 suy ra 8180>4200 suy ra \(\frac{1}{8^{180}}< \frac{1}{4^{200}}\)suy ra \(\left(\frac{-1}{8}\right)^{180}< \left(\frac{-1}{4}\right)^{200}\)
\(\left(\frac{1}{8}\right)^{100}và\left(\frac{-1}{4}\right)^{200}\)các bạn giúp mk với. đề bài là so sánh đó. cố giúp mk đi
ta có:1/8^100
-1/4^200=(-1/4^2)^100=1/16^100
=>1/8^100 >1/16^100
=>1/8^100 >-1/4^200
so sánh
\(\left(\dfrac{1}{16}\right)^{200}\) và \(\left(\dfrac{1}{2}\right)^{1000}\)
\(\left(\dfrac{1}{16}\right)^{200}< \left(\dfrac{1}{2}\right)^{1000}\)
So Sánh : \(\left(\dfrac{1}{16}\right)^{200}\)và\(\left(\dfrac{1}{2}\right)^{1000}\)
16 = 24
(\(\dfrac{1}{16}\))200 = \(\dfrac{1}{2^{4.200}}\) = \(\dfrac{1}{2^{800}}\)= (\(\dfrac{1}{2}\))800
So sánh với (\(\dfrac{1}{2}\))1000
Hai phân số cùng tử số, phân số nào có mẫu lớn hơn thì phân số đó nhỏ hơn
Suy ra: (\(\dfrac{1}{16}\))200 > (\(\dfrac{1}{2}\))1000
Ta có: \(\left(\dfrac{1}{16}\right)^{200}=\left(\dfrac{1}{2}\right)^{800}\)
mà \(\left(\dfrac{1}{2}\right)^{800}>\left(\dfrac{1}{2}\right)^{1000}\)
nên \(\left(\dfrac{1}{16}\right)^{200}< \left(\dfrac{1}{2}\right)^{1000}\)
Bài 1 : So sánh :
\(\left(\frac{1}{16}\right)^{200}\)và \(\left(\frac{1}{2}\right)^{1000}\)
Bài 2 : Tính :
\(\left(6^9.2^{10}+12^{10}\right):\left(2^{19}.27^3+15.4^9.9^4\right)\)
làm được bài 1:
TA CÓ: \(\left(\frac{1}{16}\right)^{200}=\left(\frac{1}{16}\right)^{200}\)
\(\left(\frac{1}{2}\right)^{1000}=\left(\frac{1}{2}\right)^{5.200}=\left(\frac{1^5}{2^5}\right)^{200}=\left(\frac{1}{32}\right)^{200}\)
vì mũ số bằng nhau nên ta so sánh phân số. Vì \(\frac{1}{16}>\frac{1}{32}\)nên \(\left(\frac{1}{16}\right)^{200}>\left(\frac{1}{32}\right)^{200}\)do đó\(\left(\frac{1}{16}\right)^{200}>\left(\frac{1}{2}\right)^{1000}\)
So sánh các số :
\(\left(\frac{1}{2}\right)^1;\left(\frac{1}{3}\right)^{-1};\left(\frac{1}{2}\right)^2;\left(\frac{1}{4}\right)^{-1};\left(\frac{1}{3}\right)^{-2}\)
(1/2)^-1=2
(1/2)^-2=4
có 2<4
=>(1/2)^-1<(1/2)^-2
Ta có :
\(\left(\frac{1}{2}\right)^{-1}=\left(2^{-1}\right)^{-1}=2\)
\(\left(\frac{1}{3}\right)^{-1}=3\)
\(\left(\frac{1}{2}\right)^{-2}=\left(2^{-1}\right)^{-2}=2^2=4\)
\(\left(\frac{1}{4}\right)^{-1}=\left(4^{-1}\right)^{-1}=4\)
\(\left(\frac{1}{3}\right)^{-2}=\left(3^{-1}\right)^{-2}=3^2=9\)
Do đó ta có :
\(\left(\frac{1}{2}\right)^{-1}< \left(\frac{1}{3}\right)^{-1}< \left(\frac{1}{2}\right)^{-2}=\left(\frac{1}{4}\right)^{-1}< \left(\frac{1}{3}\right)^{-2}\)