+0  
 
0
64
1
avatar

Factor completely: x^8 - 12x^4 - 64.

 Sep 13, 2020
 #1
avatar+10319 
+1

Factor completely: x^8 - 12x^4 - 64.

 

Hello Guest!

 

\(x^8 - 12x^4 - 64 \)

\(u=x^4\)

\(u^2-12u-64=0\)

           p         q

\(u=-\frac{p}{2}\pm\sqrt{(\frac{p}{2})^2-q}\\ u=6\pm\sqrt{36+64}\\ u=6\pm 10\)

\(u_{1,2}=16\\ u_{3,4}=-4 \)

\(u=x^4\)

\(x^8 - 12x^4 - 64 \)

\(=(x^4-16)(x^4+4)\\ =(x^2+4)(x+2)(x-2)(x^4+4)\)

laugh  !

 Sep 13, 2020

48 Online Users