Question Number 177331 by mr W last updated on 03/Oct/22

Answered by a.lgnaoui last updated on 04/Oct/22
![a^2 +b^2 +c^2 =(a+b+c)^2 −2(ab+bc+ac)=4 ab+bc+ac=−2 (1)( a^4 +b^4 +c^4 =(a^2 +b^2 +c^2 )^2 −2[(ab)^2 +(bc)^2 +(ac)^2 ] a^4 +b^4 +c^4 =4^2 −2[(ab+bc+ac)^2 −(ab×bc+ab×ac+bc×ab+bc×ac+ac×bc+ac×ab)= 4^2 −2[(ab+bc+ac)^2 −2(ab×bc+ab×ac+bcac)] 4^2 −2[(ab+bc+ac)^2 −2abc(a+b+c)] =4^2 −2[(−2)^2 −0]=8 donc a^4 +b^4 +c^4 =8](https://www.tinkutara.com/question/Q177337.png)
Commented by mr W last updated on 04/Oct/22

Commented by mr W last updated on 04/Oct/22

Commented by mr W last updated on 04/Oct/22

Commented by Ar Brandon last updated on 04/Oct/22

Commented by Ar Brandon last updated on 04/Oct/22

Commented by mr W last updated on 04/Oct/22

Commented by Ar Brandon last updated on 04/Oct/22
It's true Sir. But we may also use zoom in, zoom out, fit width.
Commented by mr W last updated on 04/Oct/22
