System.print(8.cbrt)        // expect: 2
System.print(1000000.cbrt)  // expect: 100
System.print(1.cbrt)        // expect: 1
System.print((-0).cbrt)     // expect: -0
System.print(0.cbrt)        // expect: 0
System.print(-2.cbrt)       // expect: -1.2599210498949