题库搜索>问题求解PS-14429
建议使用官方纸质指南，查看对照完整题目
【OG20-P166-129题】
According to a certain estimate, the depth N(t), in centimeters, of the water in a certain tank at t hours past 2:00 in the morning is given by N(t)=−20(t−5)2 + 500 for 0 ≤ t ≤ 10. According to this estimate, at what time in the morning does the depth of the water in the tank reach its maximum?
分析A选项
分析B选项
分析C选项
分析D选项
分析E选项
我有更好的解析 
暂无雷哥网文字解析
题目：据估算，某水槽中的水深（单位为厘米）N（t）在凌晨2点以后t小时
可表示为N（t）=-20(t-5)2+500,其中0≦t≦10.问根据这种估算，早上几点钟水槽中的水深达到最大值？
解：N（t）=-20(t-5)2+500=500-20(t-5)2，(t-5)2≧0，因此要使N（t）最大，则t应取值5，所以水深在2:00以后5个小时达到最大，即早上7:00.
373961gg
t是2:00过后的t个小时，不是具体的时间！！= =
0
0
回复
2020-05-19 10:46:49
emily666
考的就是个概念啊。。。又想复杂了
1
0
回复
2020-04-02 18:28:03
科目：
问题求解PS
来源：
OG17新题
题目信息1m27s
平均耗时
92.7%
平均正确率
该题由网友teV13PL提供
点击上传问题求解PS -17801
If is defined to be the product of（n+k）（n-k+ 1) for all positive integers k and n, which of the following expressions represents ?
问题求解PS -17780
If C is the temperature in degrees Celsius and F is the temperature in degrees Fahrenheit, then the relationship between temperatures on the two scales is expressed by the equation 9C＝5(F-32). On a day when the temperature extremes recorded at a certain weather station differed by 45 degrees ...
问题求解PS -17778
A certain manufacturer uses the function C(x)=0.04x2 -8.5x+25,000 to calculate the cost,in dollars, of producing x thousand units of its product. The table above gives values of this cost function for values of x between 0 and 50 in increments of 10. For which of the following in...
问题求解PS -17554
For any positive integer x, the 2-height of x is defined to be the greatest nonnegative integer n such that 2n is a factor of x. If k and m are positive integers, is the 2-height of k greater than the 2-height of m ?(1) k > m(2) k/m is an even integer.
问题求解PS -17544
The function f is defined for each positive three-digit integer n by f(n)= 2x3y5z , where x, y and z are the hundreds, tens, and units digits of n, respectively. If m and v are three-digit positive integers such that f(m) = 9f(v), then m-v = ?
问题求解PS -17801
If is defined to be the product of（n+k）（n-k+ 1) for all positive integers k and n, which of the following expressions represents ?
问题求解PS -17780
If C is the temperature in degrees Celsius and F is the temperature in degrees Fahrenheit, then the relationship between temperatures on the two scales is expressed by the equation 9C＝5(F-32). On a day when the temperature extremes recorded at a certain weather station differed by 45 degrees ...
问题求解PS -17778
A certain manufacturer uses the function C(x)=0.04x2 -8.5x+25,000 to calculate the cost,in dollars, of producing x thousand units of its product. The table above gives values of this cost function for values of x between 0 and 50 in increments of 10. For which of the following in...
问题求解PS -17554
For any positive integer x, the 2-height of x is defined to be the greatest nonnegative integer n such that 2n is a factor of x. If k and m are positive integers, is the 2-height of k greater than the 2-height of m ?(1) k > m(2) k/m is an even integer.
问题求解PS -17544
The function f is defined for each positive three-digit integer n by f(n)= 2x3y5z , where x, y and z are the hundreds, tens, and units digits of n, respectively. If m and v are three-digit positive integers such that f(m) = 9f(v), then m-v = ?
分享
周末、晚班滚动开班 
24+35+35+6课时 
