Anyone?
simplify using log properties ?
\[\large a \ln b = \ln b^a\] \[\large \ln a - \ln b = \ln\left(\dfrac{a}{b}\right)\]
i need a set of solutions for this inequality i know those..but i get stuck at some point
where exactly you got stuck
so i did this: 2ln(1-x)-ln(2x+6)<=0 2ln(1-x)/ln(2x+6)<=0 2ln(1-x)<= 0 and 2ln(2x+6)>=0 and idk what to do with this anymore xD
lets work it step by step
lets :D
\[\large 2 \ln(1-x) - \ln (2x+6) \le 0\]
step 1 : for the first term, use the log property \(\large a \ln b = \ln b^a\) \[\large \ln(1-x)^2 - \ln (2x+6) \le 0\]
okay..
next use the second log property \[\large \ln \left(\dfrac{(1-x)^2}{ (2x+6)} \right)\le 0\]
still wid me ? :)
yup
next change it to exponent form using below : \(\ln a = b \) means \(a = e^b\)
\[\large \ln \left(\dfrac{(1-x)^2}{ (2x+6)} \right)\le 0\] \[\large \dfrac{(1-x)^2}{ (2x+6)} \le e^0\] \[\large \dfrac{(1-x)^2}{ (2x+6)} \le 1\] \[\large (1+x)^2 \le 2x+6\]
see if you can solve that inequality ^
\[\large (1\color{Red}{-}x)^2 \le 2x+6 ~~^*\]
so i have x^2-4x-5<=0 and then i just do it like a normal equation right? :D
yes factor it first
english is my 3rd language so i'm not quite sure what that means >_<
can you factor the quadratic ?
x^2-4x-5<=0 (x )(x )<=0
right right i do xD we just do that differently
x1/2=... thing :D
ohkay, what do u get after u factor it ? :)
5 and -1
since the leading coefficient is positive, the graph between these zeroes stays negative, so the solutions will be : -1 <= x <= 5
however, from the first term of given given equation, x must be less than 1 (why ? )
but it says here that the correct answer is [-1,1) :/
so the final solutions will be : -1 <= x < 1
(1−x)2/(2x+6)≤1 because of this or..
\[\large 2 \color{red}{\ln(1-x) }- \ln (2x+6) \le 0\]
that part ^
since log cannot suck in negative values or 0 : 1-x > 0 x < 1
got it! thank you :)
Join our real-time social learning platform and learn together with your friends!