x^4+ 2016x^2 +2017x +2016 =?
Các bạn giúp với :))
Tính giá trị biểu thức :
a, N = \(x^6-2017x^5+2017x^4-2017x^3+2017x^2-2017x+2025\)
tại x = 2016
b, Q = \(2017x^{2016}+2016x^{2015}+2015x^{2014}+...+3x^2+2x+1\)
tại x = ( -1 )
a/ Với \(x=2016\Rightarrow2017=x+1\)
\(A=x^6-\left(x+1\right)x^5+\left(x+1\right)x^4-\left(x+1\right)x^3+\left(x+1\right)x^2-\left(x+1\right)x+2025\)
\(A=x^6-x^6-x^5+x^5+x^4-x^4-x^3+x^3+x^2-x^2-x+2025\)
\(A=2025-x=9\)
b/ Với \(x=-1\Rightarrow\left\{{}\begin{matrix}x^{2k}=1\\x^{2k+1}=-1\end{matrix}\right.\) ta có:
\(Q=2017-2016+2015-2014+...+3-2+1\)
\(Q=1+1+1+...+1+1\) (có \(\frac{2016}{2}+1=1009\) số 1)
\(Q=1009\)
Tính giá trị tại x = 2016
a (x) = x21 - 2017x20 + 2017x19 - 2017x18 + ... + 2017x3 - 2016x2 + 2016x - 1
phân tích thành nhân tử :
\(x^4+2017x^2+2016x+2017\)
GIÚP MÌNH VỚI !!!
\(x^4+2017x^2+2016x+2017\)
\(=\left(x^4+x^2+1\right)+2016\left(x^2+x+1\right)\)
\(=\left(x^4+2x^2+1-x^2\right)+2016\left(x^2+x+1\right)\)
\(=\left[\left(x^2+1\right)-x^2\right]+2016\left(x^2+x+1\right)\)
\(=\left(x^2+x+1\right)\left(x^2-x+1\right)+2016\left(x^2+x+1\right)\)
\(=\left(x^2+x+1\right)\left(x^2-x+2017\right)\)
\(x^4+2017x^2+2016x+2017\)
\(=\left(x^4-x\right)+\left(2007x^2+2007x+2007\right)\)
\(=x.\left(x^3-1\right)+2007.\left(x^2+x+1\right)\)
\(=x.\left(x-1\right)\left(x^2+x+1\right)+2007.\left(x^2+x+1\right)\)
\(=\left(x^2+x+1\right)\left(x^2-x+2007\right)\)
/x+1/2015/+/x+2/2015/+...+/x+2016/2015/=2017x
các bạn làm ơn giúp mình với ! mình gấp lắm
Ta có: \(\left|x+\frac{1}{2015}\right|\ge0\)
\(\left|x+\frac{2}{2015}\right|\ge0\)
...
\(\left|x+\frac{2016}{2015}\right|\ge0\)
\(\Rightarrow\left|x+\frac{1}{2015}\right|+\left|x+\frac{2}{2015}\right|+...+\left|x+\frac{2016}{2015}\right|\ge0\)
\(\Rightarrow2017x\ge0\)
\(\Rightarrow x\ge0\)
\(\Rightarrow\left|x+\frac{1}{2015}\right|+\left|x+\frac{2}{2015}\right|+...+\left|x+\frac{2016}{2015}\right|=x+\frac{1}{2015}+x+\frac{2}{2015}+...+x+\frac{2016}{2015}=2017x\)
\(\Rightarrow2016x+\left(\frac{1}{2015}+\frac{2}{2015}+...+\frac{2016}{2015}\right)=2017x\)
\(\Rightarrow x=\frac{1+2+...+2016}{2015}\)
Vậy \(x=\frac{1+2+...+2016}{2015}\)
Bạn cần số cụ thể thì tính ra nhé!
(2017x-2016)^3+(2016x-2015)^3=(4033x-4031)^3
Đặt 2017x-2016=a; 2016x-2015=b
Theo đề, ta có: \(a^3+b^3=\left(a+b\right)^3\)
\(\Leftrightarrow3ab\left(a+b\right)=0\)
\(\Leftrightarrow x\in\left\{\dfrac{2016}{2017};\dfrac{2015}{2016};\dfrac{4031}{4033}\right\}\)
Cho:
( 2017x1 - 2016y2 )2 + ( 2017x2 - 2016y2 )2 + ... + ( 2017x2016 - 2016x2016)2 \(\le\)0
Chứng minh \(\frac{x_1+x_2+...+x_{2016}}{y_1+y_2+...+y_{2016}}=\frac{2016}{2017}\)
( 2017x1 - 2016y2 )2 + ( 2017x2 - 2016y2 )2 + ... + ( 2017x2016 - 2016x2016)2
Chẳng có quy luật gì cả :)))
Hình như sai đề
----
sửa đề: \(\left(2017x_1-2016y_1\right)^2+\left(2017x_2-2016y_2\right)^2+....+\left(2017x_{2016}-2016y_{2016}\right)^2\le0\)
\(\text{ Ta có: }VT\ge0\text{ mà }VP\le0\)
Dấu = xảy ra khi: \(\left(2017x_1-2016y_1\right)^2+\left(2017x_2-2016y_2\right)^2+....+\left(2017x_{2016}-2016y_{2016}\right)^2=0\)
\(\Rightarrow2017x_1-2016y_1=0;2017x_2-2016y_2=0;.....;2017x_{2016}-2016y_{2016}=0\)
\(\Rightarrow2017x_1=2016y_1;2017x_2=2016_{y2};.....\text{và }2017x_{2016}=2016y_{2016}\)
\(\Rightarrow x_1=\frac{2016y_1}{2017};x_2=\frac{2016y_2}{2017};....;x_{2016}=\frac{2016y_{2016}}{2017}\)
=> \(\frac{x_1+x_2+x_3+...+x_{2016}}{y_1+y_2+y_3+...+y_{2016}}=\frac{\frac{2016.\left(y_1+y_2+...+y_{2016}\right)}{2017}}{y_1+y_2+...+y_{2016}}=\frac{2016}{2017}\)(đpcm)
Cho đa thức P(x) = x4-2017x3+2017x2-2017x+2017
Tính P(2016)
Giúp mình với, khó quá!
P(2016)= 20164-2017.20163+2017.20162-2017.2016+2017
P(2016)=1
mk mới học lớp 5 lên ko bit
Phân tích đa thức thành nhân tử:
X^4+2017x^2+2016x+2017
Ta có : x^4+2017x^2+2016x+2017
=x^4+x^3-x^3+x^2-x^2+2017x^2+2017x-x+2017
=x^4+x^3+x^2-x^3-x^2-x+2017x^2+2017x+2017
=x^2(x^2+x+1)-x(x^2+x+1)+2017(x^2+x+1)
=(x^2+x+1)(x^2-x+2017)
Nhớ k mk nha
Ta có : x^4+2017x^2+2016x+2017
=x^4+x^3-x^3+x^2-x^2+2017x^2+2017x-x+2017
=x^4+x^3+x^2-x^3-x^2-x+2017x^2+2017x+2017
=x^2(x^2+x+1)-x(x^2+x+1)+2017(x^2+x+1)
=(x^2+x+1)(x^2-x+2017)
chúc cậu hok tốt _@
Cho P= x2016-2017x15+2017x14-....-2017x+2017 với x=2016 . tính P=?
MÌNH CẦN GIÚP GẤP Ạ!!! CẢM ƠN!!!
2017 = 2016 + 1 = x + 1
suy ra 2017x15 = x16 + x15
2017x14 = x15 + x14
....
từ đó ta dễ tính ra A