如何保持健康的英文作文

如何保持健康的英文作文

People are beginning to attach much more importance to their health these days than ever before. They begin to realize that good healthis the most valuable possession a person can have. However，many people don't know how to stay healthy although great efforts have been made in this regard. In my opinion，there are three things we can do if we want to be in good.
First，we should have the right food，because proper nutrition is the most important for good health. Avoid foods with lots of sugar and fat. Eat plenty of high protein foods，vegetables and fruits. Do not overeat. Secondly，we should get proper amount of sleep，because without enough sleep，we will often feel tired and irritable. Allow ourselves at least eight hours of sleep each day. Have a nap at noon if time permits. Finally，we should exercise regularly，because'life depends on exercise'. Regular exercise strengthens our hearts andlungs. In addition，it prevents us from putting on weight.
If everyone is to do so，there will be much less complaining about poor health and there will be much more happiness in our life.

英語短文如何保持健康

People are beginning to attach much more importance to their health these days than everbefore.Theybegin to realize that good healthis the most valuable possession a person canhave.However，many people don't know how to stay healthy although great efforts have been made in thisregard.Inmy opinion，there are three things we can do if wewant to be in good.
First，we should have the right food，because proper nutrition is the most important for goodhealth.Avoidfoods with lots of sugar andfat.Eatplenty of high protein foods，vegetables andfruits.Donotovereat.Secondly，we should get proper amount of sleep，because without enough sleep，we will often feel tired andirritable.Allowourselves at least eight hours of sleep eachday.Havea nap at noon if timepermits.Finally，we should exercise regularly，because'life depends on exercise'.Regular exercise strengthens our heartsandlungs.Inaddition，it prevents us from putting on weight.
If everyone is to do so，there will be much less complaining about poor health and there will be much more happiness in our life.

已知函數f（x）=ba^x的影像經過點A（1,6），B（3,24）
（1）求f（x）

函數f（x）=ba^x的影像經過點A（1,6），B（3,24），將這兩點代入函數
則有ab=6，ba^3=24，
兩式相除，則有a^2=4，
則a=2或-2，由於f（x）=ba^x中a必須大於0，
所以a=2，則b=3
求f（x）=3×2^x

若x减y等於5，則14减2x加2y等於

14减2x加2y
=14-2（x-y）
=14-2*5
=4
不懂可追問，有幫助請採納，謝謝！

設二維隨機變數（X，Y）的概率密度為
（x，y）=「Ce∧｛-（2x+y）｝，x>0 y>0 |
| 0，其他」
求常數C？
過程寫一下吧，謝謝
還有這道題
http://zhidao.baidu.com/question/521518934？quesup2&oldq=1

由於概率密度f（x，y）要滿足歸一化條件∫∫f（x，y）dxdy=1，所以本題中∫∫Ce^（-2x-y）dxdy=1，積分區域為第一象限.囙此C∫dy∫e^（-2x-y）dx=1，x，y的積分限都是0到正無窮，∫dy∫e^（-2x-y）dx計算後=1/2，所以C=2.

matlab中繪圖，如何顯示出坐標軸（x軸和y軸）？
繪圖命令如下：
x=0:0.1:10；
y=sin（x）；
plot（x，y）
但是我要同時也顯示坐標軸（x軸和y軸），
請問如何使用命令？
我的坐標軸（x軸和y軸）的意思是：x軸指的是y=0這條直線，y軸指的是x=0這條直線，
或者說如何把坐標軸的交點弄在原點（0,0）吧

x=0:0.1:10；y=sin（x）；plot（x，y）xlabel（'X'）；ylabel（'Y'）；axis（[0,10，-1.2,1.2]）；set（gca，'XTickMode'，'manual'，'XTick'，[0 1 2 3 4 5 6 7 8 9 10]）；set（gca，'YTickMode'，'manual'，'YTick'，[-1 0 1]）；grid

根據6.4除以0.8=6寫出一道除法算式和一道乘法算式
明天要交.

6.4除以0.8=8
6.4除以8=0.8
0.8*8=6.4

周長是20釐米的長方形，長與寬的比是2:3，長和寬各是多少釐米

∵長方形有兩條長和寬且相等
∴長寬之和為：20÷2=10（釐米）
設每份為x釐米.
則可列出方程：
2x+3x=10
5x=10
∴x=2
則2x=4（釐米）（長）
3x=6（釐米）（寬）
答：這個長方形的長為4釐米，寬為6釐米.

二次函數的一般式怎樣化為頂點式.

y=ax^2+bx+c
=a[x^2+bx/a]+c
=a[x^2+bx/a+（b/2a）^2-（b/2a）^2]+c
=a[（x+b/（2a））^2-b^2/（4a^2）]+c
=a[x+b/（2a）]^2-b^2/（4a）+c

已知多項式-2X²；+3與A兩倍的差是2X²；+2X-7（方程解答，
（1）求多項式A
（2）當A=-1時，求A的值

（1）依題意得：
（-2x²；+3）-2A=2x²；+2x-7
∴2A=-4x²；-2x+10
A=-2x²；-x+5
（2）當x=-1時
A=-2x²；-x+5
=-2×（-1）²；-（-1）+5
=4