Finding Local Extrema Find all the local maxima, local minima, and saddle points of the functions in Exercises 1-30. 1. f(x, y) = x² + xy + y² + 3x · - 3y+4 = - 2xy 5.x2 - 2y² + 4x + 4y 4 2. f(x, y) 3. f(x, y) 4. f(x, y) 5. f(x, y) 6. f(x, y) = = = = = 7. f(x, y) 8. f(x, y) = 9. f(x, y) = 10. f(x, y) = 11. f(x, y) 12. f(x, y) 13. f(x, y) = = = = x² + xy + 3x + 2y + 5 - 5xy - 7x² + 3x 6y + 2 2xy x22y2 + 3x + 4 x² - 4xy + y²+ 6y + 2 2x² + 3xy+4y² x² - 2xy + 2y² x² — y². - x² + 2xy √56x2 - - - - 5x + 2y 2x + 2y + 1 2x + 4y + 6 8y2 1 - √√√x² + y² - 16x ― 3118x = x³ — y³ — 2xy + 6