On 4/06/2011 3:16 PM, ross kyprianou wrote:
> Can anyone please suggest the best way to find the real solutions to
> inequalities involving exp() such as
> exp(-4*x)>1/2
> Neither solve nor fourier_elim seem to help
>
> (%i13) load(fourier_elim)$
> (%i16) fourier_elim([exp(-4*x)>1/2],[x]);
>
> 4 x
> (%o16) [2 - %e > 0]
>
> Hope you can help
> Ross
(%i1) display2d:false;
(%o1) false
(%i2) load(fourier_elim)$
(%i3) exp(-4*x)>1/2;
(%o3) %e^-(4*x) > 1/2
(%i4) map(log,%);
(%o4) -4*x > -log(2)
(%i5) fourier_elim([%],[x]);
(%o5) [x < log(2)/4]