Does the sign change? F(x) = LN (-6 - x)

[jenjen]

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]

yes ... the inequality changes direction when multiplying both sides of the inequality by a negative value.

 

[tkhunny]

-x>6
x<-6
Is the sign supposed to change? since I divided by a negative?

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]

thank you!