To get the extrema, derive the function.
You get y' = 2x^-1/3 - 2.
Set this equal to zero, and you get x=0 as the location of a critical point.
Since you are on a closed interval [-1, 1], those points can also have an extrema.
Your min is right, but the max isn't at (1,1). At x=-1, you get y=5 (y = 3(-1)^2/3 -2(-1); (-1)^2/3 = 1, not -1).
Thus, the maximum is at (-1, 5).
Answer: the number of tiles will be 49
Step-by-step explanation:
Let x represent the number of tiles that Joshua can buy at either stores.
one store for $0.99 per tile but he he will have to rent a tile saw for $25. Let the total cost of buying x tiles in this store be y. Therefore
y = 0.99x + 25
At another store, he can buy a tile for $1.50 per tile and borrow a tile saw for free. Let the total cost of buying x tiles in this store be z. Therefore
z = 1.5x
To determine the number of tiles for which both costs will be the same, we will equate y to z. It becomes
0.99x + 25 = 1.5x
1.5x - 0.99x = 25
0.51x = 25
x = 25/0.51
x = 49
