Help solving equation
HoMoon115
Q = 10L - 1/2000 (L)squared
Is it possible to solve for L in this equation?
Thanks,
Aaron
--
submissions: post to k12.ed.math or e-mail to k12...@k12groups.org
private e-mail to the k12.ed.math moderator: kem-mo...@k12groups.org
newsgroup website: http://www.thinkspot.net/k12math/
newsgroup charter: http://www.thinkspot.net/k12math/charter.html
ticbol
Sure it is possible, but L will be in terms of Q only.
Q = 10L - 1/2000 (L)squared
I assume the -1/2000 (L)squared is -(1/2000)(L^2) so that the given
equation is quadratic only.
[If it were -1/(2000 L^2), then the given equation would be cubic.]
Q = 10L -(1/2000)(L^2)
Q = 10L -0.0005(L^2)
Put them all to the lefthand side,
0.0005(L^2) -10L +Q = 0
Use the Quadratic Formula,
L = {-(-10) +,-sqrt[(-10)^2 -4(0.0005)(Q)]} / (2* 0.0005)
L = {10 +,-sqrt[100 -(0.002)Q]} / 0.001
L = 10,000 +,-1000sqrt[100 -0.002Q]
That means,
L = 10,000 +1000sqrt[100 -0.002Q] ----***
or,
L = 10,000 -1000sqrt[100 -0.002Q] ----***
Duane Bozarth
HoMoon115 wrote:
>
> Q = 10L - 1/2000 (L)squared
>
> Is it possible to solve for L in this equation?
Q = 10L - 0.0005L^2 ?
If that's what you mean, ever hear of the quadratic formula?
Duane Bozarth
HoMoon115 wrote:
>
> Q = 10L - 1/2000 (L)squared
>
> Is it possible to solve for L in this equation?
Perhaps second post,sorry...had more to add.
Ever hear of quadratic formula? (The old b and +/- sqrt(4ac) thingy...)
Yes in terms of Q but not numerically unless you select a value for Q.
Otherwise, you have only one equation w/ two unknowns...
And, of course, there are limits on what Q can be if you wish to
restrict the solution to the real line rather than the complex plane...
More about what you want/need would be helpful...
Jeffrey Turner
HoMoon115 wrote:
> Q = 10L - 1/2000 (L)squared
>
> Is it possible to solve for L in this equation?
Sure is. You now know how many Ls make a Q, how do you think
you'd find out how many Qs you'd need for an L?
--Jeff
--
But I venture the challenging statement
that if American democracy ceases to
move forward as a living force, seeking
day and night by peaceful means to
better the lot of our citizens, then
Fascism and Communism, aided, unconsciously
perhaps, by old-line Tory Republicanism,
will grow in strength in our land.
--Franklin Delano Roosevelt
Kevin Karplus
On 2005-10-04, HoMoon115 <homo...@yahoo.com> wrote:
>
> Q = 10L - 1/2000 (L)squared
>
> Is it possible to solve for L in this equation?
Yes.
Assuming that the equation you meant to write was
Q = 10 L - (1/2000) L^2 ,
this is a standard quadratic formula and can be solved with any of the
techniques taught in Algebra 1 for solving quadratics.
------------------------------------------------------------
Kevin Karplus kar...@soe.ucsc.edu http://www.soe.ucsc.edu/~karplus
Professor of Biomolecular Engineering, University of California, Santa Cruz
Undergraduate and Graduate Director, Bioinformatics
(Senior member, IEEE) (Board of Directors, ISCB)
life member (LAB, Adventure Cycling, American Youth Hostels)
Effective Cycling Instructor #218-ck (lapsed)
Affiliations for identification only.
MA Math Teacher
Yes.
Jim Spriggs
HoMoon115 wrote:
>
> Q = 10L - 1/2000 (L)squared
>
> Is it possible to solve for L in this equation?
L = 2000(5 +/- sqrt(25 + Q/2000))
--
I don't know who you are Sir, or where you come from,
but you've done me a power of good.
ticbol
Let me try answering this again. Looks like my answer 3 days ago would
not be not posted.anymore.
Q = 10L -(1/2000)L^2
Q = 10L -0.0005L^2
0.0005L^2 -10L +Q = 0
Use the Quadratic Formula,
L = {-(-10) +,-sqrt[(-10)^2 -4(0.0005)(Q)]} / (2*0.0005)
L = {10 +,-sqrt[100 -0.002Q]} / 0.001
L = {10 +,-sqrt[100(1 -0.00002Q)]} / (1/1000)
L = {10 +,-10sqrt[1 -0.00002Q]} * (1000)
L = 10,000 [1 +,-sqrt(1 -0.00002Q)]
That is it.