# solve and calculate

 0 How can I solave an equation like x+z^2=1 and then calculate x with z=3 from the solution? Thanks. asked Jan 26 '12 Mebus 5 ● 2 If you think you have made a mistake in your question you can edit your question. Please do not post duplicate.Shashank (Jan 26 '12)

 1 z=var('z') solve(x+z^2==1,x)[0].substitute(z==3)  posted Jan 26 '12 Shashank 1720 ● 8 ● 30 ● 62 This works, but is there also a more comfortable way to write this:solve(energiebilanz, h51x)[0].substitute(c_luft=12m/s, mw=(1/3600)kg/s, hw=146.68J/g, TL=313K)maybe like in a set of parameters?Thanks.Mebus (Jan 27 '12)This works, but is there also a more comfortable way to write this:solve(energiebilanz, h51x)[0].substitute(c_luft=12m/s, mw=(1/3600)kg/s, hw=146.68J/g, TL=313K)Mebus (Jan 27 '12)
 1 A variation on the Shashank'answer : sage: z=var('z') sage: f(z)=solve(x+z^2==1,x)[0].rhs() sage: f z |--> -z^2 + 1 sage: f.diff(z) z |--> -2*z sage: f.plot()  Here you consider the function "solution of the equation as function of z", and you do whatever with it. posted Jan 27 '12 Laurent Claessens 354 ● 4 ● 8 ● 22 http://homepages.ulb.ac.b...

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