A domain is a set of all first elements of ordered pairs (x-coordinates) The range is the set of second elements of ordered pairs (Y-coordinates) Domain and range can be seen clearly on the graphic
The rate of change in z at (4,9) as we change x but hold y fixed is =
3/[2sqrt(3x+2y)] put x = 4 , y = 9 = 3/[2sqrt(12+18) = 3/[2sqrt(30)] The
rate of change in z at (4,9) as we change y but hold x fixed is =
1/sqrt(3x+2y) put x = 4, y =9 = 1/sqrt(30)
Answer: Rachel's prediction is faster than the actual unit rate, and Theadore's prediction is slower.