搜题请搜索小程序“爱下问搜题”
问题 填空题
义域分别是Df，Dg的函数y=f（x），y=g（x），规定：函数h（x）=
f(x)•g(x)     (x∈Df且x∈Dg)
f(x)     (x∈Df且x∉Dg)
g(x)   (x∉Df且x∈Dg)
，
若函数f（x）=-2x+3，x≥1；g（x）=x-2，X∈R．则函数h（x）的解析式为______，函数h（x）的最大值为______．
答案

（1）由于函数f（x）=-2x+3，g（x）=x-2，根据题意得：

当x≥1时，h（x）=f（x）g（x）=（-2x+3）（x-2）=-2x2+7x-6；

当x＜1时，h（x）=g（x）=x-2．

所以h(x)=

-2x2+7x-6  (x≥1)
x-2                 (x＜1) 
．

（2）当x≥1时，h（x）=-2x2+7x-6=--(x-

7
4
)2+
1
8
，因此，当x=
7
4
时，h（x）最大，h（x）的最大值为
1
8
．

若x＜1时，h（x）=x-2＜1-2=-1．

∴函数h（x）的最大值为 

1
8
．

单项选择题

Louis Armp had two famous nicknames. Some people called him Bagamo. They said his mouth looked like a large bag. Musicians often called him Pops, as a sign of respect for his influence on the world of music.
Born in 1901 in New Orleans, he grew up poor, but lived among great musicians. Jazz had been invented in the city a few years before his birth. Armp often said, "Jazz and I grew up together. "
Armp showed a great talent for music when he was taught to play the comet at a boy’s home. In his late teens, Armp began to live the life of a musician, lie played in parades, clubs, and on the steamboats that traveled on the Mississippi River. At that time, New Orleans was famous for the new music of jazz and was home to many great musicians. Armp learned from the older musicians and soon became respected as their equal.
In 1922 he went to Chicago. There, the tale of Louis Armp began. From then until the end of his life, Armp was celebrated and loved wherever he went. Armp had no equal when it came to playing the American popular song.
His cornet playing had a deep humanity and warmth that caused many listeners to say, "Listening to Pops just makes you feel good all over. " He was the father of the jazz style and also one of the best known and most admired people in the world. His death, on July 6th 1971,was headline news around the world.

Which would be the best title for the text

A．The Invention of the Jazz Music
B．The Father of the Jazz Style
C．The Making of a Musician
D．The Spread of Popular Music
查看答案
单项选择题 A1型题

风邪袭表证候的脉象特点是()

A.浮滑

B.浮紧

C.浮数

D.浮弦

E.浮缓
查看答案