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Mimi_x3
 5 years ago
The polynomial P(x) = x^3  2x^2 + kx + 24 has roots a , b and γ
(i) It is known that two of the roots are equal in magnitude but opposite in sign.
Find the third root and hence find the value of k
Can you please help .
Mimi_x3
 5 years ago
The polynomial P(x) = x^3  2x^2 + kx + 24 has roots a , b and γ (i) It is known that two of the roots are equal in magnitude but opposite in sign. Find the third root and hence find the value of k Can you please help .

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Mimi_x3
 5 years ago
Best ResponseYou've already chosen the best response.0:@ ?? why yu angry ? LOL

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0just having a bad day

Mimi_x3
 5 years ago
Best ResponseYou've already chosen the best response.0lols , having a bad day ? why ?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I passed the entry test to uni, but apparently, I need to get minimum of 2 A levels to get into it. A levels take 2 years to get. I have 4 months.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I got so far (for roots a,a and c) 3a +c = 2 and a^2 c = 24 U get that?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I don't mean understand, I mean u calculated same?

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0I said for roots, a,a and c

Mimi_x3
 5 years ago
Best ResponseYou've already chosen the best response.0ohh lols , i dnt even know how to do it

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0There is similar (not same) formula like Vieta for cubic as for quadratic....

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Formulae for sum and product of roots of quadratic.

anonymous
 5 years ago
Best ResponseYou've already chosen the best response.0Let a be the first root >0. Then b=a Now since a cubic function with 3 real roots then must be of the form: (xa)(xb)(xv)= x^3  2x^2 + kx + 24 But b=a so LHS is (xa)(x+a)(xv)=(x^2a^2)(xv) Multiplying the left hand side out we get: =x^3v*x^2a^2*x+v*a^2=P(x) From this we see that v=2 which implies 24=2*a^2 then a^2=12 but a^2*x=kx thus k=12
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