Pregunta: 67-70 Describe the level surfaces of the function. х 67. f(x, y, z) = x + 3y + 5z 68. f(x, y, z) = x2 + 3y2 + 5z2 69. f(x, y, z) = y2 + z2 70. f(x, y, z) = x2 - y2 – 22 24. f(x, y) = x2 23-31 Sketch the graph of the function. 23. f(x, y) = y 25. f(x, y) = 10 – 4x – 5y 26. f(x, y) = cos y 27. f(x, y) = sin x 28. f(x, y) = 2 – x2 - y2 29. f(x, y) = x2 + 4y2

67-70 Describe the level surfaces of the function. х 67. f(x, y, z) = x + 3y + 5z 68. f(x, y, z) = x2 + 3y2 + 5z2 69. f(x, y, z) = y2 + z2 70. f(x, y, z) = x2 - y2 – 22 24. f(x, y) = x2 23-31 Sketch the graph of the function. 23. f(x, y) = y 25. f(x, y) = 10 – 4x – 5y 26. f(x, y) = cos y 27. f(x, y) = sin x 28. f(x, y) = 2 – x2 - y2 29. f(x, y) = x2 + 4y2 + 1 30. f(x, y) = 4x2 + y2 31. f(x, y) = 14 - 4x2 - y2