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avatar+1405 

Help Me please.

 

Quadratic form: Solve the equations and do not include any extraneous roots

 

x4-2x2-8=0

 Mar 8, 2018
 #1
avatar+99397 
+1

x^4  - 2x^2   - 8  = 0        factor

 

(x^2 - 4)  (x^2 + 2)   =0

 

(x - 2)  (x + 2)  (x^2  + 2)  = 0

 

Set the   factors   = 0    and solve

 

x  - 2 = 0      x +  2  =0                     x^2  + 2   = 0

x  = 2            x  = -2                         x^2   = -2        take both roots

                                                         x  = √-2        x  = - √2

                                                          x  = i√2        x  =    -i √2

 

 

 

cool cool cool

 Mar 8, 2018
 #2
avatar+1405 
+1

thanks

 Mar 8, 2018

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