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The restorative power of sleep is graphically approximated by the function −x2 + 16x + 36, where the x-axis measures sleeping hours and the y-axis measure the restoration value. After how many hours does sleep no longer perform restorative duties according to the function?
  • a)
    −2
  • b)
    4
  • c)
    8
  • d)
    13
  • e)
    18
Correct answer is option 'E'. Can you explain this answer?
Verified Answer
The restorative power of sleep is graphically approximated by the func...
To determine when sleep no longer performs restorative duties according to the function −x2 + 16x + 36, we need to find the x-coordinate of the vertex.
The x-coordinate of the vertex of a quadratic function in the form ax2 + bx + c can be found using the formula:
x = -b / (2a)
In this case, the function is −x2 + 16x + 36, so a = -1, b = 16, and c = 36.
Using the formula, we have:
x = -16 / (2*(-1))
x = -16 / (-2)
x = 8
Therefore, the vertex of the function occurs at x = 8. However, we need to determine after how many hours sleep no longer performs restorative duties. Since the function is a downward-facing parabola, the restoration value decreases as x increases beyond the vertex.
As x increases beyond 8, the restoration value will continue to decrease. We can observe this by calculating the restoration value at x = 8 and x = 9:
At x = 8:
Restoration value = -82 + 16(8) + 36 = -64 + 128 + 36 = 100
At x = 9:
Restoration value = -92 + 16(9) + 36 = -81 + 144 + 36 = 99
As x increases further, the restoration value will continue to decrease. Therefore, after 8 hours of sleep, according to the function, sleep no longer performs restorative duties.
Hence, the correct answer is E: 18.
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Most Upvoted Answer
The restorative power of sleep is graphically approximated by the func...
To determine when sleep no longer performs restorative duties according to the function −x2 + 16x + 36, we need to find the x-coordinate of the vertex.
The x-coordinate of the vertex of a quadratic function in the form ax2 + bx + c can be found using the formula:
x = -b / (2a)
In this case, the function is −x2 + 16x + 36, so a = -1, b = 16, and c = 36.
Using the formula, we have:
x = -16 / (2*(-1))
x = -16 / (-2)
x = 8
Therefore, the vertex of the function occurs at x = 8. However, we need to determine after how many hours sleep no longer performs restorative duties. Since the function is a downward-facing parabola, the restoration value decreases as x increases beyond the vertex.
As x increases beyond 8, the restoration value will continue to decrease. We can observe this by calculating the restoration value at x = 8 and x = 9:
At x = 8:
Restoration value = -82 + 16(8) + 36 = -64 + 128 + 36 = 100
At x = 9:
Restoration value = -92 + 16(9) + 36 = -81 + 144 + 36 = 99
As x increases further, the restoration value will continue to decrease. Therefore, after 8 hours of sleep, according to the function, sleep no longer performs restorative duties.
Hence, the correct answer is E: 18.
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In recent years, a class of drugs known as COX-2 inhibitors has gotten much publicity for the drugs’ power to relieve inflammation and pain. These drugs are relatively new to the pharmaceutical industry, their mechanisms of action having been discovered only in 1971. That year, John Vane discovered the relationship between nonsteroidal antiinflammatory drugs, such as aspirin, and a group of molecules, called prostaglandins, responsible for producing the sensation of pain in the human body, among other functions.Prostaglandins were first discovered in the 1930s and are now known to be generated by most mammalian tissues in response to external stimuli. Unlike classical hormones that are synthesized in one tissue but act on a distant one, prostaglandins act on the cells that produce them or on cells located close to the prostaglandins’ cells of origin.Aspirin alleviates pain by inhibiting the function of an enzyme called cyclooxygenase or COX; this inhibition prevents the production of prostaglandins. The three forms of this enzyme, COX-1, COX-2, and COX-3, all stimulate the production of prostaglandins, but each serves a different purpose. COX-1 functions to protect the stomach from irritating gastric acids. COX-2 functions to induce inflammation in injured tissue and COX-3 functions to control the sensation of pain. Aspirin and other similar drugs, such as naproxen, inhibit both COX-1 and COX-2, sometimes producing or aggravating stomach ulcers in patients who take them.In order to eliminate the side effects of aspirin and related drugs, several pharmaceutical companies in the 1990s developed drugs that inhibited only COX-2. However, side effects almost always cropped up, even after clinical trials that seemed to indicate none. This often occurs because trials are conducted within very limited parameters; once the drug has been approved for mass distribution, however, the number of people taking it and the length of time that it is taken increase dramatically. Several COX-2 drugs that have been popular in recent years fit this pattern: initially successful in clinical trials, subsequent studies showed them to have serious, potentially lethal side effects.Though prostaglandin chemistry and enzymology have been studied for half a century, pinpointing the exact role of the molecules in physiological processes still remains a challenge for researchers. Hence it is not surprising that recent therapeutic attempts to interfere with the formation of certain prostaglandins have produced unexpected side effects. It now seems that the hype surrounding COX-2 drugs may have been premature.Q. According to the passage, all of the following are true of prostaglandins EXCEPT

In recent years, a class of drugs known as COX-2 inhibitors has gotten much publicity for the drugs’ power to relieve inflammation and pain. These drugs are relatively new to the pharmaceutical industry, their mechanisms of action having been discovered only in 1971. That year, John Vane discovered the relationship between nonsteroidal antiinflammatory drugs, such as aspirin, and a group of molecules, called prostaglandins, responsible for producing the sensation of pain in the human body, among other functions.Prostaglandins were first discovered in the 1930s and are now known to be generated by most mammalian tissues in response to external stimuli. Unlike classical hormones that are synthesized in one tissue but act on a distant one, prostaglandins act on the cells that produce them or on cells located close to the prostaglandins’ cells of origin.Aspirin alleviates pain by inhibiting the function of an enzyme called cyclooxygenase or COX; this inhibition prevents the production of prostaglandins. The three forms of this enzyme, COX-1, COX-2, and COX-3, all stimulate the production of prostaglandins, but each serves a different purpose. COX-1 functions to protect the stomach from irritating gastric acids. COX-2 functions to induce inflammation in injured tissue and COX-3 functions to control the sensation of pain. Aspirin and other similar drugs, such as naproxen, inhibit both COX-1 and COX-2, sometimes producing or aggravating stomach ulcers in patients who take them.In order to eliminate the side effects of aspirin and related drugs, several pharmaceutical companies in the 1990s developed drugs that inhibited only COX-2. However, side effects almost always cropped up, even after clinical trials that seemed to indicate none. This often occurs because trials are conducted within very limited parameters; once the drug has been approved for mass distribution, however, the number of people taking it and the length of time that it is taken increase dramatically. Several COX-2 drugs that have been popular in recent years fit this pattern: initially successful in clinical trials, subsequent studies showed them to have serious, potentially lethal side effects.Though prostaglandin chemistry and enzymology have been studied for half a century, pinpointing the exact role of the molecules in physiological processes still remains a challenge for researchers. Hence it is not surprising that recent therapeutic attempts to interfere with the formation of certain prostaglandins have produced unexpected side effects. It now seems that the hype surrounding COX-2 drugs may have been premature.Q. The passage suggest which the following about COX2 inhibitors?

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The restorative power of sleep is graphically approximated by the function −x2 + 16x + 36, where the x-axis measures sleeping hours and the y-axis measure the restoration value. After how many hours does sleep no longer perform restorative duties according to the function?a)−2b)4c)8d)13e)18Correct answer is option 'E'. Can you explain this answer?
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