Pregunta: 3-20 Find the local maximum and minimum values and saddle point(s) of the function. If you have three-dimensional graphing software, graph the function with a domain and viewpoint that reveal all the important aspects of the function. 3. f(x, y) - 9 - 2x + 4y - x - 4y2 4. f(x, y) = 2x2 + 3y2 – 5x + 4y 5. f(x, y) = (x + 1)2 + (y – 2)2 - 4 6. f(x, y) = xy +

3-20 Find the local maximum and minimum values and saddle point(s) of the function. If you have three-dimensional graphing software, graph the function with a domain and viewpoint that reveal all the important aspects of the function. 3. f(x, y) - 9 - 2x + 4y - x - 4y2 4. f(x, y) = 2x2 + 3y2 – 5x + 4y 5. f(x, y) = (x + 1)2 + (y – 2)2 - 4 6. f(x, y) = xy + 12x? – 8y 7. f(x, y) = x² + xy + y2 + y 8. f(x, y) = xy – 2x – 2y – x2 - y2 9. f(x, y) = (x - y)(1 – xy) 10. f(x, y) = (1 + xy)(x + y) 11. f(x, y) = xy(1 - x - y) 12. f(x, y) = 2x + xy2 + 5x² + y2 13. f(x, y) = y3 + 3x²y – 6x2 – 6y2 + 2 14. f(x, y) = 2 - ** + 2x² - y2 + 15. f(x, y) = x - 12xy + 8y3 16. f(x, y) = xy + 17. f(x, y) =xe-2-2y? 18. 6, 18. f(x,y) - e4y=x?-y? 19. f(x, y) = (x² + y²) 20. f(x, y) = e"(y2 – *)