f(2x+1)=3x-1,f(a)=4,a=___用換元法解

f(2x+1)=3x-1,f(a)=4,a=___用換元法解


設a=2x+1
f(a)=f(2x+1)=3x-1=4
x=5/3
a=2x+1=13/3



求函數的值域換元法f(x)=2x^2-2X+3/X^2+3X+5只要算灋
還有f(x)=X+6/X的解法或影像謝


y=(2x^2-2x+3)/(x^2+3x+5)
整理得(y-2)x^2 +(3y+2)x+5y+3 =0
方程必有根,Δ≥0解出y的範圍即為值域
第二題是y=(x+6)/x還是y= x +6/x
y=(x+6)/x = 1+ 6/x
6/x≠0∴y≠1
y= x +6/x
當x>0 y= x +6/x≥2√6【利用均值不等式a+b≥2√ab】
當x



你是一名教師?用英語翻譯


Are you a teacher?



【英語翻譯】我希望當一名像他一樣的老師.


I want to be a teacher like him.



英文翻譯一句話謝謝.一名剛學一年唱歌的人就能成為一名歌唱家,這是不可能的.


一名剛學一年唱歌的人就能成為一名歌唱家,這是不可能的.
①It is impossible for someone to become a singer with only one year of experience.
②It is impossible for someone with only one year of experience to become a singer.
③It is impossible for a person to become a singer with only one year of practice.
你們那裡有沒有很冷了?小白你那裡冷嗎?



英語翻譯


His mother is an English teacher of Peking University.



我爸爸的小轎車她是一名英語老師用英語翻譯


my father's car
She is an English teacher.



他以前是一比特英語老師現在是翻譯用英文怎麼說


He used to be an Englishteacher.andnow he is a translator.



英語翻譯
是Can you sing or dance well?還是Can you sing well or dance well?
這個題其實是讓你把I can sing well(dance)改為選擇疑問句


網上,查到一些回答
多數人選擇的是Can you sing or dance well?
我明天幫您問問我英語好的朋友.
我也打算幫您轉發問題,讓更多人參與回答.有更好的回答,我迴響給您



英語翻譯:我喜歡**(比如跳舞),可惜只是還沒有機會去嘗試


I like **,unfortunately,haven't got the change to do it.