\(^2\sqrt[\log_{\ge}]{}\)
bpt logarit đưa về cùng cơ số :
1, \(2lg\left[\left(x-1\right)\sqrt{5}\right]>lg\left(x-5\right)+1\)
2, \(log_{\dfrac{1}{2}}\left[log_2\left(3^x+1\right)\right]>-1\)
3, \(log_x\dfrac{3x-1}{x^2+1}>0\)
4, \(\left(0,08\right)^{log_{x-0,5}x}\ge\left(\dfrac{5\sqrt{2}}{2}\right)^{log_{x-0,5}\left(2x-1\right)}\)
Tìm TXĐ:
a) y=\(\left(1-x\right)^{\dfrac{-1}{3}}\)
b) \(y=\sqrt{\log_{0,5}\dfrac{2x+1}{x+5}-2}\)
c) \(y=\log_{10}\sqrt{x^2-x-12}\)
d) \(y=\sqrt{\log_{10}x-1+\log_{10}x+1}\)
1.rút gọn A=3\(\log_4\sqrt{a}\)- \(\log_{\dfrac{1}{2}}a^2\)+ 2\(\log_{\sqrt{2}}a\)
2.bt \(\log_23=a\). tính \(\log_{12}36\) theo a
1.
\(A=3log_{2^2}\sqrt{a}-log_{2^{-1}}a^2+2log_{a^{\dfrac{1}{2}}}a\)
\(=3.\dfrac{1}{2}.\dfrac{1}{2}log_2a-\left(-1\right).2.log_2a+2.2.log_2a\)
\(=\dfrac{27}{4}log_2a\)
2.
\(log_{12}36=\dfrac{log_236}{log_212}=\dfrac{log_2\left(3^2.2^2\right)}{log_2\left(3.2^2\right)}=\dfrac{log_23^2+log_22^2}{log_23+log_22^2}\)
\(=\dfrac{2.log_23+2}{log_23+2}=\dfrac{2a+2}{a+2}\)
giải bpt logarit đưa về cùng cơ số
1, \(2lg\left[\left(x-1\right)\sqrt{5}\right]>lg\left(x-5\right)+1\)
2, \(log_{\dfrac{1}{2}}\left[log_2\left(3^x+1\right)\right]>-1\)
3, \(log_x\dfrac{3x-1}{x^2+1}>0\)
4, \(\left(0,08\right)^{log_{0,5-x}x}\ge\left(\dfrac{5\sqrt[]{2}}{2}\right)^{log_{x-0,5}\left(2x-1\right)}\)
- Ai đó làm giúp với nhé
Bất phương trình logarit
$$1) \sqrt{log_{1/2}^{2} \frac{2x}{4-x} - 4} \leq \sqrt{5}$$
$$2)log_{2}(x-1)^{2} > 2log_{2} (x^{3} +x +1)$$
$$3)\frac{1}{log_{2}(4x)^{2} +3 } + \frac{1}{log_{4} 16x^{3}-2} <-1$$
$$4)log_{2} (4^{x}+4) < log_{\frac{1}{2}} (2^{x+1} -2)$$
tính
a) \(log_{\sqrt{2}}\sqrt{2};log_77\)
b) \(log_{10}1;log_91\)
c) \(3^{log_315};7^{log_7\sqrt{2}}\)
d) \(log_88^{-10};log_55^{\sqrt{3}}\)
\(log_{\sqrt{2}}\sqrt{2}=1;log_77=1\)
\(log_{10}1=0;log_91=0\)
\(3^{log_35}=5;7^{log_7\sqrt{2}}=\sqrt{2}\)
\(log_88^{-10}=-10;log_55^{\sqrt{3}}=\sqrt{3}\)
\(log_{\sqrt{3}}\left(\sqrt[5]{3}\right)=?\)
\(log_24.log_{\dfrac{1}{4}}2=?\)
\((\log_{2} (4x))^2-\log_{\sqrt{}2} (2x)=5\)
\(\left[log_24x\right]^2-log_{\sqrt{2}}2x=5\)
=>\(\left[log_2\left(2\cdot2x\right)\right]^2-log_{2^{\dfrac{1}{2}}}2x=5\)
=>\(\left[1+log_22x\right]^2-1:\dfrac{1}{2}\cdot log_22x=5\)
=>\(\left(log_22x\right)^2+2\cdot log_22x+1-2\cdot log_22x=5\)
=>\(\left(log_22x\right)^2=4\)
=>\(\left[{}\begin{matrix}log_22x=2\\log_22x=-2\left(loại\right)\end{matrix}\right.\Leftrightarrow log_22x=2\)
=>\(2x=2^2=4\)
=>x=2
m=? để \(log_{2\sqrt{2}+\sqrt{7}}\left(x-m+1\right)log_{2\sqrt{2}-\sqrt{7}}\left(mx-x^2\right)=0\)có nghiệm
ban solo voi minh khong