solve x^500 - x + 0.4 = 0   |   plot x^500 - x + 0.4
"solve" does not always provide the solutions. What to do?
I only know that the solutions are about 0.4 and 1
We look for the two solutions with better precision.

plot x^500 - x + 0.4, 0.39 < x < 0.41

...
plot x^500 - x + 0.4, 0.399996 < x < 0.400004

fisrt solution: 4.0000000

min x^500 - x + 0.4
≈ 0.98762
plot x^500 - x + 0.4, 0.98762 < x < 1

...
plot x^500 - x + 0.4, 0.998973 < x < 0.998977

second solution: 0.998975