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).
The best thing to do is to find what 1% is, and you can do this by dividing 150 by 100.
150/100= 1.5
As you're looking for 6.5%, you've got to multiply 1.5 by 6.5
1.5*6.5= 9.75
You've then got to add 9.75 and 150 together
150+9.75= $159.75
Therefore, after the sales tax, the cost of the necklace is $159.75
Hope this helps :)
Answer:
C(7,-8)
R= 8
The general formula of a circle = (x-a)+(y-b)=r²
