Math Is Fun Forum
You are not logged in.
- Topics: Active | Unanswered
#1 2007-08-19 21:34:48
- tony123
- Member
- Registered: 2007-08-03
- Posts: 229
solve
Offline
#2 2007-08-19 22:43:23
- JaneFairfax
- Member
- Registered: 2007-02-23
- Posts: 6,868
Re: solve
For such problems, you can often use trial & error and see if it leads you anywhere. In your particular question, x = 1 is one solution. Now try and spot some more (if there are any more). 
Offline
#3 2007-08-30 01:55:12
- kmadhyan
- Member
- Registered: 2007-08-30
- Posts: 4
Re: solve
I think there is no integer solution other then 1
x^2+2^(x-1/x)-2^(2-1/x)
=>x^2=2^2*2^(-1/x)-2^x*2^(1/x)
on solving it gives
X^2=2^x-2^(x-1/x)/2^1/x
Since the denominator is 2^1/x so other than 1 it would be non rational value..........
IT is maths which has brought humanity from Ice Age to Present 
Offline
#4 2007-09-04 11:11:40
- truegirl90
- Member
- Registered: 2007-09-04
- Posts: 1
Re: solve
an airplane travels at a rate of 7 miles per minute for 120 minutes. find the distance traveled using d=rt
Offline
#5 2007-09-04 18:50:45
- krassi_holmz
- Real Member
- Registered: 2005-12-02
- Posts: 1,905
Re: solve
It's the only solution. Look at a plot of the above function to see it's strictly increasing for x>1 and x<-1.
IPBLE: Increasing Performance By Lowering Expectations.
Offline
#6 2007-09-05 10:23:34
- John E. Franklin
- Member
- Registered: 2005-08-29
- Posts: 3,588
Re: solve
truegirl90, 120 + 120 + 120 + 120 + 120 + 120 + 120 = 840 miles.
When you multiply the fraction of miles over minutes times minutes.
The (miles/minutes) times (minutes)...
The minutes on the top divided by the minutes on bottom just makes 1 (one).
So you are left with miles. So the answer is in miles.
minutes and miles are called units, and in chemistry class in high school, you will see the units have to make sense.
Other units are: weight, force, mass, volume, temperature, pressure, moles, etc.
igloo myrtilles fourmis
Offline