2010x² + -1x + -2011 = 0

<=> -2011 + -1x + 2010x2 = 0

<=> -2011 + -1x + 2010x2 = 0

<=> (-1 + -1x)(2011 + -2010x) = 0

=> -1 + -1x = 0 hoặc 2011 + (-2010x) = 0

=> x = -1 hoặc x = \(\frac{2011}{2010}\)

mik nghĩ đề sai lẽ ra phải là P=\(\dfrac{2010+2011\sqrt{1-x^2}+2012}{\sqrt{1-x^2}}\)(\(-1\le x\le1\))

P=\(\dfrac{2010}{\sqrt{1-x^2}}+2011+\dfrac{2012}{\sqrt{1-x^2}}=\dfrac{2010}{\sqrt{\left(1-x\right)\left(1+x\right)}}+\dfrac{2012}{\sqrt{\left(1-x\right).\left(1+x\right)}}+2011\)

áp dụng BDT CÔ SI \(\sqrt{\left(1-x\right)\left(1+x\right)}\le\dfrac{1-x+1+x}{2}=1\)

=>\(\dfrac{2010}{\sqrt{\left(1-x\right)\left(1+x\right)}}\ge2010\left(1\right)\)

tương tự \(\dfrac{2012}{\sqrt{\left(1-x\right)\left(1+x\right)}}\ge2012\left(2\right)\)

cộng vế (1)(2)=>\(\dfrac{2010}{\sqrt{\left(1-x\right)\left(1+x\right)}}+\dfrac{2012.}{\sqrt{\left(1-x\right)\left(1+x\right)}}\ge2012+2010=4022\)

=>\(\dfrac{2010}{\sqrt{\left(1-x\right)\left(1+x\right)}}+\dfrac{2012}{\sqrt{\left(1+x\right)\left(1-x\right)}}+2011\ge4022+2011=6033\)

dấu = xảy ra khi và chỉ khi x=0

vậy min P=6033

Ta có: x = 2011 \(\Rightarrow\) 2010 = x - 1

\(A=x^{2011}-2010x^{2010}-2010x^{2009}-...-2010x+1\)

\(=x^{2011}-\left(x-1\right)x^{2010}-\left(x-1\right)x^{2009}-...-\left(x-1\right)x+1\)

\(=x^{2011}-\left(x-1\right)x^{2010}-\left(x-1\right)x^{2009}-...-\left(x-1\right)x+1\)

\(=x^{2011}-x^{2011}+x^{2010}-x^{2010}+x^{2009}-...-x^2+x+1\)

\(=x+1\)

\(=2011+1\)

\(=2012.\)

x=2011

=> 2010= x-1

A = x^2011- (x-1) x^2010- (x-1).x^2009-.....- (x-1).x+1

= x^2011-x^2011+x^2010- x^2010+x^2009..x^2.-x^2+x+1

= x+1

=(x-1)+2= 2010+2=2012

ĐS: 2011x+1

Đúng ko ? :p

x.x^4 nha

-Ta thấy \(x^4+x^2+1=x^4-x+x^2+x+1=\left(x^2-x\right)\left(x^2+x+1\right)+\left(x^2+x+1\right)=\left(x^2-x+1\right)\left(x^2+x+1\right)\)

Vậy PT sẽ thành

\(\frac{2010x\left(x^3+1\right)}{x\left(x^4+x^2+1\right)}+\frac{2010x\left(x^3-1\right)}{x\left(x^4+x^2+1\right)}=\frac{2011}{x\left(x^4+x^2+1\right)}\)

\(\Leftrightarrow2.2010x^4=2011\Leftrightarrow x=...\)

Bài 2:

Ta có : \(2010=2011-1=x-1\)

Thay \(2010=x-1\) vào biểu thức A ,có :

\(x^{2011}-\left(x-1\right)x^{2010}-\left(x-1\right)x^{2009}-...-\left(x-1\right)x+1\)

\(=x^{2011}-x^{2011}+x^{2010}-x^{2010}+x^{2009}-...-x^2+x+1\)

\(=x+1\)

\(=2011+1=2012\)

Vậy giá trị biểu thức A là 2012

Bài 3:

\(a+b+c=0\)

\(\Rightarrow a+b=-c\)

\(\Rightarrow\left(a+b\right)^2=\left(-c\right)^2\)

\(\Rightarrow a^2+2ab+b^2=c^2\)

\(\Rightarrow a^2+b^2-c^2=-2ab\left(1\right)\)

Tương tự :

\(a+b+c=0\)

\(\Rightarrow a+c=-b\)

\(\Rightarrow\left(a+c\right)^2=\left(-b\right)^2\)

\(\Rightarrow a^2+2ac+c^2=b^2\)

\(\Rightarrow a^2+c^2-b^2=-2ac\left(2\right)\)

\(a+b+c=0\)

\(\Rightarrow b+c=-a\)

\(\Rightarrow\left(b+c\right)^2=\left(-a\right)^2\)

\(\Rightarrow b^2+c^2-a^2=-2bc\left(3\right)\)

Từ (1)(2)(3)

\(\Rightarrow A=\dfrac{-ab}{2ab}+\dfrac{-bc}{2bc}+\dfrac{-ac}{2ac}\)

\(=\dfrac{-abc-abc-abc}{2abc}=\dfrac{-3abc}{2abc}=-\dfrac{3}{2}\)