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27 tháng 7 2017

integral_(3/4 + 1/(4 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) - 1/2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))))^(3/4 + 1/(4 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) + 1/2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3))))) (-2 - 5 x + 4 x^2 - 3 x^3 + x^4) dx = -2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) - 1/5 (3/4 + 1/(4 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) - 1/2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))))^5 + 1/5 (3/4 + 1/(4 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) + 1/2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))))^5 - 5 (-1/2 (3/4 + 1/(4 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) - 1/2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))))^2 + 1/2 (3/4 + 1/(4 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) + 1/2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))))^2) + 4 (-1/3 (3/4 + 1/(4 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) - 1/2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))))^3 + 1/3 (3/4 + 1/(4 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) + 1/2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))))^3) - 3 (-1/4 (3/4 + 1/(4 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) - 1/2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))))^4 + 1/4 (3/4 + 1/(4 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))) + 1/2 sqrt(-5/6 + 53/3 (2/(353 + 3 sqrt(80013)))^(1/3) - 1/3 (1/2 (353 + 3 sqrt(80013)))^(1/3) + 19/2 sqrt(3/(-5 - 212 (2/(353 + 3 sqrt(80013)))^(1/3) + 2 2^(2/3) (353 + 3 sqrt(80013))^(1/3)))))^4)≈-10.0747

PS: Bài này cũng không chắc nhé

27 tháng 7 2017

Dùng hệ phương trình vào giải:
\(x^4-3x^3+4x^2-5x-2\)

\(\Leftrightarrow x\left\{x\left[\left(x-3\right)x+4\right]-5\right\}-2\)

\(\Rightarrow x=\left\{0;1\right\}\)

Vậy nghiêm là 0 hoặc 1

16 tháng 2 2019

Rút gọn ta được :

\(f\left(x\right)=x^4+2x^2+1=\left(x^2+1\right)^2\)

Dễ thấy \(x^2+1>0\)

\(\Rightarrow\left(x^2+1\right)^2>0\)

=> đa thức vô nghiệm ( đpcm )

8 tháng 4 2020

\(f\left(x\right)=5x^3+2x^4-x^2+3x^2-x^3-x^4+1-4x^3\)\(=x^4+2x^2+1=\left(x^2+1\right)^2\)Dễ thấy \(x^2+1>0\)

=>\(\left(x^2+1\right)^2>0\)(Điều phải chứng minh)

4 tháng 8 2016

a/ 2x3 ‐5x2 + 8x ‐3

= 2x3 ‐x2 ‐4x2 +2x +6x ‐3

= x2 (2x‐1) ‐ 2x(2x‐1) + 3.(2x‐1)

= (x2‐2x+3) (2x‐1) 

b/ 3x3 ‐ 14x2 +4x +3

= 3x3 +x2 ‐15 x2 ‐5x +9x +3

= x2(3x+1) ‐5.x (3x+1) +3. (3x+1) 

= (x2 ‐5x+3) (3x+1) 

2 tháng 7 2018

Giúp mình với

7 tháng 8 2016

a) 2x3-5x2+8x-3

=2x3-x2-4x2+2x+6x-3

=x2(2x-1)-2x(2x-1)+3(2x-1)

=(2x-1)(x2-2x+3)

6 tháng 9 2017

a,2x3-5x2+8x-3

=2x3-x2-4x2+2x+6x-3

=x2(2x-1)-2x(2x-1)+3(2x-1)

=(2x-1)(x2-2x+3) 

14 tháng 7 2016

nhìu quá @@