lo g 2 x − 6 lo g x 2 = 5
Can the equation above be solved?
This section requires Javascript.
You are seeing this because something didn't load right. We suggest you, (a) try
refreshing the page, (b) enabling javascript if it is disabled on your browser and,
finally, (c)
loading the
non-javascript version of this page
. We're sorry about the hassle.
Given that
lo g 2 x − 6 lo g x 2 lo g 2 x − 6 ⋅ lo g 2 x lo g 2 2 lo g 2 x − 6 ⋅ lo g 2 x 1 lo g 2 2 x − 5 lo g 2 x − 6 ( lo g 2 x − 6 ) ( lo g 2 x + 1 ) = 5 = 5 = 5 = 0 = 0
⟹ lo g 2 x = ⎩ ⎨ ⎧ 6 − 1 ⟹ x = 2 6 = 6 4 ⟹ x = 2 − 1 = 2 1
Yes , it can be solved.
The name of the question is because it came from the deep recesses of my brain (quote taken from Dr. Frost)
Log in to reply
Hi Yajat, what is happening with problems II and III in this series? I've seen from notifications that you've replied to reports, but it's not possible for users to view those replies and still be able to answer the questions. It doesn't look like the problems have been edited.
Log in to reply
I am in school. Wait until 3 : 3 0 pm.
Problem Loading...
Note Loading...
Set Loading...
Let u = lo g 2 x so that we obtain the quadratic equation:
u − u 6 = 5 ⇒ u 2 − 5 u − 6 = ( u − 6 ) ( u + 1 ) = 0 ⇒ u = − 1 , 6 .
which gives back lo g 2 x = − 1 , 6 ⇒ x = 2 1 , 6 4 . Since x ∈ R + , the answer is YES.