A river 100 ft wide is flowing north at w feet per second. A dog starts at (100, 0) and swims at vo = 4 ft/s, always heading toward a tree at (0, 0) on the west bank directly across from the dog's...

Extracted text: A river 100 ft wide is flowing north at w feet per second. A dog starts at (100, 0) and swims at vo = 4 ft/s, always heading toward a tree at (0, 0) on the west bank directly across from the dog's starting point. show that the dog reaches the tree. If w = 2 ft/s,