Select the intervals for which the average rate of change of the function is -0.5. f(x)=12/x

A. 1 ≤ × ≤ 6

B. 2≤ × ≤ 3

C. 2 ≤ × ≤ 12

D. 3 ≤ × ≤ 6

E. 3 ≤ × ≤ 12

F. 4 ≤ × ≤ 6

G. 4 ≤ × ≤ 12

answer: 204

step-by-step explanation:

we are told that the revenue is

x⋅(4080−10x)=−10x^2+4080x

this is a quadratic function, so to maximize it we should find the x-value of its vertex. recall that the x-value of the vertex of the parabola ax^2+bx+c is given by the formula −b/2a.

so in this case, we have a=−10 and b=4080, so the x-value of the vertex is

−b/2a= −(4080)/2(−10)=204

step-by-step explanation:

left be aligning the decimal points is required to not required see the number of digits to the right