mng giúp mik vs , mik cảm ơn mng
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3:
#include <bits/stdc++.h>
using namespace std;
double x,y;
int main()
{
cin>>x>>y;
cout<<fixed<<setprecision(2)<<sqrt(x*x+y*y);
return 0;
}
Bn ơi bn viết r chụp lên đc k ạ ? Mik k định dạng đc ý
a, Theo tc 2 tt cắt nhau: \(AE=EC;BF=CF\)
Vậy \(AE+BF=EC+CF=EF\)
b, Vì \(\left\{{}\begin{matrix}AE=EC\\\widehat{EAO}=\widehat{ECO}=90^0\\OE.chung\end{matrix}\right.\) nên \(\Delta AOE=\Delta COE\)
\(\Rightarrow\widehat{AOE}=\widehat{EOC}\) hay OE là p/g \(\widehat{AOC}\)
Cmtt: \(\Delta BOF=\Delta COF\Rightarrow\widehat{BOF}=\widehat{COF}\) hay OF là p/g \(\widehat{BOC}\)
Vậy \(\widehat{EOF}=\widehat{COF}+\widehat{COE}=\dfrac{1}{2}\left(\widehat{AOC}+\widehat{BOC}\right)=90^0\) hay OE⊥OF
IX
2. j
3. i
4. f
5. c
6. a
7. h
8. e
9. g
10. d
XI
2. part => parts
3. a => an
4. a => an
5. a => the
6. are => will be (không chắc lắm)
7. taking => take
8. are => is
C.
Bài 1
1. C
2. B
3. C
4. B
(Nên double-check trước khi chép)
18, \(\frac{x}{2}+\frac{x^2}{8}=0\Leftrightarrow4x+x^2=0\Leftrightarrow x\left(x+4\right)=0\Leftrightarrow x=-4;x=0\)
19, \(4-x=2\left(x-4\right)^2\Leftrightarrow\left(4-x\right)-2\left(4-x\right)^2=0\)
\(\Leftrightarrow\left(4-x\right)\left[1-2\left(4-x\right)\right]=0\Leftrightarrow\left(4-x\right)\left(-7+2x\right)=0\Leftrightarrow x=4;x=\frac{7}{2}\)
20, \(\left(x^2+1\right)\left(x-2\right)+2x-4=0\Leftrightarrow\left(x^2+1\right)\left(x-2\right)+2\left(x-2\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(x^2+3>0\right)=0\Leftrightarrow x=2\)
21, \(x^4-16x^2=0\Leftrightarrow x^2\left(x-4\right)\left(x+4\right)=0\Leftrightarrow x=0;x=\pm4\)
22, \(\left(x-5\right)^3-x+5=0\Leftrightarrow\left(x-5\right)^3-\left(x-5\right)=0\)
\(\Leftrightarrow\left(x-5\right)\left[\left(x-5\right)^2-1\right]=0\Leftrightarrow\left(x-5\right)\left(x-6\right)\left(x-4\right)=0\Leftrightarrow x=4;x=5;x=6\)
23, \(5\left(x-2\right)-x^2+4=0\Leftrightarrow5\left(x-2\right)-\left(x-2\right)\left(x+2\right)=0\)
\(\Leftrightarrow\left(x-2\right)\left(5-x-2\right)=0\Leftrightarrow x=2;x=3\)
1. a) mẹ
b) thân mẫu
2. a) phu nhân
b) vợ
3. a) chết, lâm chung
b) lâm chung
4. a) giáo huấn
b) dạy bảo
\(A=\dfrac{\cos^217^o+2\cos^273^o}{\cot65^o\cot25^o}-\sin^217^o\)
\(A=\dfrac{\left(\cos^217^o+\cos^273^o\right)+\cos^273^o}{\tan25^o\cot25^o}-\sin^217^o\)
(áp dụng công thức \(\cot\alpha=\tan\left(90^o-\alpha\right)\))
\(A=\left(\cos^217^o+\sin^217^o\right)+\sin^217^o-\sin^217^o\)
(áp dụng công thức \(\tan\alpha.\cot\alpha=1\) và \(\cos\alpha=\sin\left(90^o-\alpha\right)\))
\(A=1\)
Answer:
a) \(P=\frac{5x-2}{x^2-4}-\frac{3}{x+2}+\frac{x}{x-2}\)
\(=\frac{5x-2}{\left(x-2\right)\left(x+2\right)}-\frac{3x-6}{\left(x+2\right)\left(x-2\right)}+\frac{x+2x}{\left(x-2\right)\left(x+2\right)}\)
\(=\frac{5x-2-3x+6+x^2+2x}{\left(x+2\right)\left(x-2\right)}\)
\(=\frac{\left(x+2\right)^2}{\left(x+2\right)\left(x-2\right)}\)
\(=\frac{x+2}{x-2}\)
b) \(\left|x+3\right|=5\)
\(\Rightarrow\orbr{\begin{cases}x+3=5\\x+3=-5\end{cases}}\Rightarrow\orbr{\begin{cases}x=2\text{(Loại)}\\x=-8\end{cases}}\)
Với \(x=-8\) thì giá trị của biểu thức P
\(P=\frac{-8+2}{-8-2}=\frac{3}{5}\)
c) \(P=\frac{x+2}{x-2}=\frac{x-2+4}{x-2}=1+\frac{4}{x-2}\)
Mà để P nguyên thì \(\frac{4}{x-2}\) nguyên
\(\Rightarrow\left(x-2\right)\inƯ\left(4\right)=\left\{\pm1;\pm2;\pm4\right\}\)
\(\Rightarrow x\in\left\{3;1;4;0;6;-2\right\}\) mà đề ra \(x\ne\pm2\)
Vậy \(x\in\left\{3;1;4;0;6\right\}\) thì P nguyên