We use cookies to personalise content and advertisements and to analyse access to our website. Furthermore, our partners for online advertising receive pseudonymised information about your use of our website. cookie policy and privacy policy.
 
+0  
 
0
68
1
avatar

Solve for x.

ln(x-1)+ln(x+2)=1

(Does it equal a rational number?)

 Feb 12, 2019
 #1
avatar+100802 
0

\(ln(x-1)+ln(x+2)=1\\ ln[(x-1)(x+2)]=1\\ e^{ln[(x-1)(x+2)]}=e^1\\ x^2+x-2=e\\ x^2+x-(2+e)=0\\\)

\(x^2+x-(2+e)=0\\ x=\frac{-1\pm\sqrt{1+4(2+e)}}{2}\\ x=\frac{-1\pm\sqrt{1+8+4e}}{2}\\ x=\frac{-1\pm\sqrt{9+4e}}{2}\\ \)

 

Those are not equal or rational solutions.

 Feb 12, 2019

14 Online Users