374: How to Factor Polynomials with Mathematica

Here is how to factor a polynomial such as
3
D
-3
2
D
+4
:
Factor[D^3-3*D^2+4]
2
(-2+D)
(1+D)
Here is how to find roots of a polynomial equation such as
3
D
-3
2
D
+4=0
.
Solve[D^3-3*D^2+40,D]
{{D-1},{D2},{D2}}