
#1
Jun1904, 05:47 PM

P: 60

Could someone please help me with this question, I'd be most obliged:
Q) Find the value of "a" for which the function 2x^3  ax^2  12x  7 has a repeated factor. Thanks 



#2
Jun1904, 06:40 PM

Emeritus
Sci Advisor
PF Gold
P: 11,154

If you mean two identical roots, then ...
write [tex] 2x^3  ax^2  12x  7 = (xb)^2(2xc) [/tex] Expand the RHS and compare coefficients. You have 3 equations in 3 unknowns. 



#3
Jul404, 12:59 AM

PF Gold
P: 1,059

Since we are seeking only a specific solution, we can keep in mind that if the cubic has a double root, that this root is also present in its derative. The derative is: 2(3X^2aX6). Here if we let a =3, we get X =2, 1. 1 works in the original equation and the factoring then is 2(x+l)^2(x7/2).



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