In Problems 1-2, find the global maximum value and global minimum value of ( on S and indicate where each occurs.
1. ((x, y) = 3x + 4y;
S = {(x, y): 0 ( x ( 1, -1 ( y ( 1}
2. ((x, y) = x2 + y2;
S = {(x, y): -1 ( x ( 3, -1 ( y ( 4}