Solve command
- To: mathgroup at smc.vnet.net
- Subject: [mg6936] Solve command
- From: TTCJ34A at prodigy.com ( JOHN C ERB)
- Date: Tue, 29 Apr 1997 20:48:16 -0400 (EDT)
- Sender: owner-wri-mathgroup at wolfram.com
Ninos Benyamin wrote:
>
> Using Mathemathica 3.0, can anyone show me how to:
> a) Complete squares
> b) Make the following Solve command work
> Solve[x^2+y^2+12x-20y+15==(x-a)^2+(y-b)^2-r^2,{a,b,r}]
> Please e-mail the response. Thanks.
> Ninos Benyamin
If you want to follow the steps of completing the square for a
specific example, try the following where you can substitute in
your own values for a, b, & c.
a=8;b=22;c=15;
Clear[x];
a x^2 + b x + c==0
a x^2 + b x == -c
x^2+(b/a) x == -c/a
x^2 + (b/a) x + (b/(2a))^2 == -c/a + (b/(2a))^2
(x + b/(2a))^2 == -c/a + (b/(2a))^2
x + b/(2a) == Sqrt[-c/a + (b/(2a))^2]
x == -b/(2a) + Sqrt[-c/a + (b/(2a))^2]
x == -b/(2a) - Sqrt[-c/a + (b/(2a))^2]
Hope this is what you're looking for.
John C. Erb