# A Simple equation [closed]

I don't know why is not working?!!

Clear["Global*"]
x[t] = x0 Exp[y0 (t - 1)];
t0 = 1; \Xi = 0.3; \Gamma = 1.33; \Lambda = 0.7;
eqns = {y0^2 - (k*(1 - 2/(3*\Gamma)))/Exp[y0*(t - t0)] - (\Xi/\Gamma)*y0 - \Lambda};
f[t_] := y0^2 - (k*(1 - 2/(3*\Gamma)))/Exp[y0*(t - t0)] - (\Xi/\Gamma)*y0 - \Lambda;
Solve[eqns == 0, y0]

• Have you tried using Solve with all of your assumptions entered? Jan 11 at 15:29
• Recommend you write eqns = {y[x]^2 - a*y[x]*Sqrt[y[x]^2 + b*x[t]^-2 - f] + b*x[t]^-2 - a*f ==0} /. y[x] -> x'[t]/x[t];` Otherwise if you run the line more than once, you'll get strange things happening. Jan 11 at 15:34
• okay, thanks for your hint. Jan 11 at 15:47
• CA Trevillian, you mean " Solve [ {eqns , x[1] == 1} , y , t ]" Jan 11 at 15:57
• You are wrong. "x'[t] / x[t] == Constant" implies an exponential, not a power law. Jan 11 at 16:41