Pregunta: use Theorem 2 to find the local extrema. 1 In Problems 17–36, 17. f(x, y) = x + 8x + y2 + 25 a n 18. f(x, y) = 15x2 - y2 - 10y 19. f(x, y) = 8 - x2 + 12x - y2 - 2y 20. f(x, y) = x2 + y2 + 6x 8y + 10 21. f(x, y) = x2 + 3xy + 2y2 + 5 22. f(x, y) = 4x2 - xy + y2 + 12 23. f(x,y) = 100 + 6xy - 4x? - 3y2 24. f(x, y) 5x2 - y2 + 2y + 6 25. f(x, y) = x2 + xy + y2 -

use Theorem 2 to find the local extrema. 1 In Problems 17–36, 17. f(x, y) = x + 8x + y2 + 25 a n 18. f(x, y) = 15x2 - y2 - 10y 19. f(x, y) = 8 - x2 + 12x - y2 - 2y 20. f(x, y) = x2 + y2 + 6x 8y + 10 21. f(x, y) = x2 + 3xy + 2y2 + 5 22. f(x, y) = 4x2 - xy + y2 + 12 23. f(x,y) = 100 + 6xy - 4x? - 3y2 24. f(x, y) 5x2 - y2 + 2y + 6 25. f(x, y) = x2 + xy + y2 - 7x + 4y + 9 26. f(x, y) = -x + 2xy – 2y2 – 20x + 34y + 40 C 27. f(x, y) = ely 28. f(x, y) = xy - xy2 29. f(x, y) = x + y3 – 3xy 30. f(x, y) = 2y3 - 6xy - x? 31. f(x, y) = 2x* + y2 - 12xy 32. f(x, y) = 16xy - x* – 2y2 33. f(x, y) = x - 3xy2 + 6y2 34. f(x,y) = 2x² – 2x²y + 6y3 935. f(x, y) = xe + xy + 1 | 36. f(x, y) = y ln x + 3xy 37. Explain why f(x, y) = x has a local extremum at infinitely many points.