The graph of the function f(x) = –(x + 6)(x + 2) is shown below. which statement about the function is true?
the function is increasing for all real values of x where
x < –4.
the function is increasing for all real values of x where
–6 < x < –2.
the function is decreasing for all real values of x where
x < –6 and where x > –2.
the function is decreasing for all real values of x where
x < –4.

The first statement is true.

Step-by-step explanation:

The function is f(x) = - (x + 6)(x + 2)  

⇒ f(x) = - x² - 8x - 12

Now, condition for a function f(x) to be increasing at x = a is f'(a) > 0.

Now, f(x) = - x² - 8x - 12

⇒ f'(x) = -2x - 8 {Differentiating with respect to x}

Now, f'(a) = -2a - 8 {Here a can be any real value}

And, the condition for increasing function at x = a is  

- 2a - 8 > 0

⇒ - 2a > 8

⇒ a < - 4

Therefore, the first statement is true i.e. the function is increasing for all real values of x where  x < – 4. (Answer)

solution:

as, mean is defined as sum of all the observations divided by total number of observations.

and , median is mid value of the data whether arranged in ascending order or descending order.

consider, roadsters:

2,3,4,5,6,7,8,9

mean =

also, median= , because number of observations is even, so median is mean of two mid values.

now, coming to bandits

2,3,4,5,6

mean =  

median = 4, as number of observations is odd.

so, roadsters has greater median as well mean than bandits.

→option a is true about the repairs performed on 2 types of cars:

bandits have lower median and mean than roadsters.

5

10

15

20

25

30

35

40

45

50

55