# Need to find value for X

• Nov 28th 2011, 06:49 AM
thashrif
Need to find value for X
http://www.coolmetron.co.uk/maths.gif

Can some one please let me know how the value for x is 2.13?

Thanks a lot.
• Nov 28th 2011, 07:04 AM
Siron
Re: Need to find value for X
What have you tried? Have you learned to solve equations yet?
• Nov 28th 2011, 09:23 AM
thashrif
Re: Need to find value for X
Quote:

Originally Posted by Siron
What have you tried? Have you learned to solve equations yet?

No I have not
• Nov 28th 2011, 08:21 PM
mathland
Re: Need to find value for X
Quote:

Originally Posted by thashrif
http://www.coolmetron.co.uk/maths.gif

Can some one please let me know how the value for x is 2.13?

Thanks a lot.

Before I can proceed, I need to know if you meant to type (1 + x^2)/12 or
1 + (x^2/12) for the numerator part of the fraction.
• Nov 29th 2011, 04:38 AM
thashrif
Re: Need to find value for X
Quote:

Originally Posted by mathland
Before I can proceed, I need to know if you meant to type (1 + x^2)/12 or
1 + (x^2/12) for the numerator part of the fraction.

Hi, Thank you very much for looking into this, the numerator part should be (1 + x^2)/12

Thanks a lot
• Nov 29th 2011, 12:04 PM
HallsofIvy
Re: Need to find value for X
So the problem is to solve $1.6911= 1.6242\frac{\frac{1+ x^2}{12}}{1.0062}$.

First do the arithmetic on the right: $\frac{1.6242}{12(1.0062)}= 0.134516$ to 6 decimal places. That means the equation is $1.611= 0.134516(1+ x^2)$. Divide both sides by 0.134516: $0.134516= x^2+ 1$.

Subtract 1 from both sides. $x^2= -0.8655$ which has no real number soltutions. if you are allowed complex numbers, the solution is plus or minus $\sqrt{0.8655}$ times i.
• Nov 29th 2011, 01:49 PM
mathland
Re: Need to find value for X
Quote:

Originally Posted by thashrif
http://www.coolmetron.co.uk/maths.gif

Can some one please let me know how the value for x is 2.13?

Thanks a lot.

I worked this problem twice and did not come close to your answer for x.

You say that x = 2.13.

If x = 2.13, then after evaluation, we should get the same answer on both sides of the equation.

Let x = 2.13

1.6199 = 1.6242 [(1 + x^2)/12)] divided by 1.0062

1.6199 = 1.6242 [(1 + (2.13)^2)/12)] divided by 1.0062

1.6199 = 1.6242 [(1 + 4.5369)/12)] divided by 1.0062

1.6199 = 1.6242 [(5.5369)/12)] divided by 1.0062

As I continued to simplify, I did not get 1.6199 on both sides of the equation. So, the answer for x that you suggested (2.13) is not correct.
Find a calculator and continue simplifying where I ended my computation. I'm sure you will agree.
• Nov 29th 2011, 07:17 PM
bjhopper
Re: Need to find value for X
Quote:

Originally Posted by thashrif
No I have not

the equality is true.
• Nov 30th 2011, 01:00 PM
BabyMilo
Re: Need to find value for X
Quote:

Originally Posted by HallsofIvy
That means the equation is $1.611= 0.134516(1+ x^2)$. Divide both sides by 0.134516: $0.134516= x^2+ 1$.

Mistake?

First it should be 1.6911 instead of 1.611.

Secondly,

$\frac{1.611}{0.134516}= 11.98 (2 d.p.)$

Correct me if I am wrong.

Quote:

Originally Posted by thashrif
Hi, Thank you very much for looking into this, the numerator part should be (1 + x^2)/12

Thanks a lot

http://www.wolframalpha.com/input/?i=1.6199+%3D+1.6242*%28%281+%2B+x^2%29%2F%2812*1. 0062%29%29+find+x