J jenjen New member Joined Jan 16, 2008 Messages 14 Apr 29, 2008 #1 F(x)=LN (-6-x) My Solution -6-x>0 -x>6 x<-6 Is the sign supposed to change? since I divided by a negative?
F(x)=LN (-6-x) My Solution -6-x>0 -x>6 x<-6 Is the sign supposed to change? since I divided by a negative?
skeeter Elite Member Joined Dec 15, 2005 Messages 3,204 Apr 29, 2008 #2 yes ... the inequality changes direction when multiplying both sides of the inequality by a negative value.
yes ... the inequality changes direction when multiplying both sides of the inequality by a negative value.
tkhunny Moderator Staff member Joined Apr 12, 2005 Messages 11,325 Apr 29, 2008 #3 jenjen said: -x>6 x<-6 Is the sign supposed to change? since I divided by a negative? Click to expand... I never liked this idea. It is just too confusing, as can be seen. Use addition and be done with it. -x > 6 Add x 0 > 6 + x Subtract 6 -6 > x Change the direction if you must. x < -6 No confusion.
jenjen said: -x>6 x<-6 Is the sign supposed to change? since I divided by a negative? Click to expand... I never liked this idea. It is just too confusing, as can be seen. Use addition and be done with it. -x > 6 Add x 0 > 6 + x Subtract 6 -6 > x Change the direction if you must. x < -6 No confusion.
