I am trying to rearrange this equation
Q=0.098[(D^4-d^4)/D]
For D=
I have spent to hours factoriseing, swapping sides, etc. but im getting nowhere.
Please Help
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I am trying to rearrange this equation
Q=0.098[(D^4-d^4)/D]
For D=
I have spent to hours factoriseing, swapping sides, etc. but im getting nowhere.
Please Help
What does "WA" mean
So "D" and "d" are different? "D" is the value you want to determine and "d" is some given value?Quote:
Originally Posted by gwood311
Multiply both sides by D:
Do the multiplication on the right and subtract QD from both sides:
Now that is a fourth degree equation. There is a "formula" for solving general fourth degree equations but it is very complicated:
Quartic function - Wikipedia, the free encyclopedia
princeps provided a link to Wolfram Alpha , an online computational site ... click on his WAQuote:
Originally Posted by gwood311
Hi friends, Algebra is really very complicated, even i was facing such problem in Algebra. You guys are really working hard and helping each by solving each other Algebra queries. You can also go for online Algebra Tutor.
Thanks for help guys. Didn't realise the WA was a hyperlink, thanks.
After looking into the 4th degree equation I found the equation must be in the format:
ax^4 + bx^2 + c=0
In my equation the middle part is not squared so I cannot solve the equation.
I am beginning the think the equation cannot be rearranged simply for D and the only answer for it is on WA provided by princeps
That equation is a quadratic; let u = x^2, then au^2 + bu + c = 0.Quote:
Originally Posted by gwood311
That equation is a quadratic; let u = x^2, then au^2 + bu + c = 0.
My equation which is; 0.098D^4 - QD - 0.098d^4 = 0
Letting u=D^2 in this case will not work.
Right. I was referring to : ax^4 + bx^2 + c = 0Quote:
Originally Posted by gwood311
0.098D^4 - QD - 0.098d^4 = 0
That one is really: 0.098D^4 + 0D^3 + 0D^2 - QD - 0.098d^4 = 0
or : 98D^4 + 0D^3 + 0D^2 - 1000QD - 98d^4 = 0