What is the equation of the circle shown in the graph?

Heat the oil in a 2-quart saucepan over medium heat. Add the onion, garlic and curry powder and cook and stir for 2 minutes.
Step 2
Stir in the soup and water and heat to a boil. Reduce the heat to low. Stir in the lentils and coconut milk and cook for 5 minutes. Season to taste with salt and pepper before serving. 1 teaspoon canola oil
1 medium onion, diced (about 1/2 cup)
1 clove garlic
1 teaspoon curry powder
1 can (10 3/4 ounces) Campbell’s® Condensed Tomato Soup
1 1/4 cups water
1 1/4 cups cooked lentils (from about 1/2 cup dry)
1/2 cup unsweetened coconut milk