SOLUTION: The solution set in interval notation of the inequality 16x-x^3≥0 is: A) [-4, 4] B) (-∞, -2]U[0, 4) C) (-∞, 0]U[1, 4) D) (-∞, 4] E) (-∞, -4]U[

Algebra ->  Functions -> SOLUTION: The solution set in interval notation of the inequality 16x-x^3≥0 is: A) [-4, 4] B) (-∞, -2]U[0, 4) C) (-∞, 0]U[1, 4) D) (-∞, 4] E) (-∞, -4]U[      Log On


   

Question 1006083: The solution set in interval notation of the inequality 16x-x^3≥0 is:
A) [-4, 4]
B) (-∞, -2]U[0, 4)
C) (-∞, 0]U[1, 4)
D) (-∞, 4]
E) (-∞, -4]U[0, 4]
Answer by josgarithmetic(39616) About Me  (Show Source):
You can put this solution on YOUR website!
x%2816-x%5E2%29%3E=0
x%284%2Bx%29%284-x%29%3E=0

Critical x values: -4,0,4;

? (-infinity,-4] ?
(-)(-)(+)>=0
TRUE

[-4,0] ?
Try -1.
(-1)(4-1)(4-(-1))=(-1)(3)(5)>=0
FALSE

[0,4] ?
Try 1
1*(4+1)(4-1)=1*5*3>=0
TRUE

[4, infinity) ?
5*(4+5)(4-5)=Negative>=0
FALSE

Solution set is (-infinity, -4] U [0,4].
Choice E.