If f(x) = ∣(x^2 − 6)(x^2 + 2)∣, how many numbers in the interval 1 ≤ x ≤ 2 satisfy the conclusion of the mean value theorem?
a. none
b. one
c. two
d. three

Question

If f(x) = ∣(x^2 − 6)(x^2 + 2)∣, how many numbers in the interval 1 ≤ x ≤ 2 satisfy the conclusion of the mean value theorem?
a. none
b. one 
c. two 
d. three

anonymous · Answer

@Abhisar @Hero @iambatman @Michele_Laino @satellite73 @TheSmartOne @Zale101

michele_laino · Answer

please note that within the interval (1,2) x^2-6 is negative

anonymous · Answer

@Michele_Laino what do you mean?

michele_laino · Answer

I meant that 
$$f(x) = \left( {6 - {x^2}} \right)\left( {{x^2} + 2} \right)$$
when x is in [1,2]

michele_laino · Answer

we have to solve this equation:
$$4{x^3} - 8x - 3 = 0$$

anonymous · Answer

oh ok

anonymous · Answer

i got 3 is that right @Michele_Laino