Function to find the change in hemispheric volume
void new_vol ( double x ) { if ( x > 0 ) { cout << " % ▁ change ▁ in ▁ the ▁ " << " volume ▁ of ▁ the ▁ hemisphere : ▁ " << pow ( x , 3 ) / 10000 + 3 * x + ( 3 * pow ( x , 2 ) ) / 100 << " % " << " ▁ increase STRNEWLINE " ; } else if ( x < 0 ) { cout << " % ▁ change ▁ in ▁ the ▁ " << " volume ▁ of ▁ the ▁ hemisphere : ▁ " << pow ( x , 3 ) / 10000 + 3 * x + ( 3 * pow ( x , 2 ) ) / 100 << " % ▁ decrease STRNEWLINE " ; } else { cout << " Volume ▁ remains ▁ the ▁ same . " ; } }