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Mimi_x3
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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 .
 2 years ago
 2 years ago
Mimi_x3 Group Title
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 .
 2 years ago
 2 years ago

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

aredsani Group TitleBest ResponseYou've already chosen the best response.0
3rd root is 2
 2 years ago

oktalBlizzard Group TitleBest ResponseYou've already chosen the best response.0
not angry
 2 years ago

oktalBlizzard Group TitleBest ResponseYou've already chosen the best response.0
just having a bad day
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.0
how is 3rd root 2 ?
 2 years ago

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

oktalBlizzard Group TitleBest ResponseYou've already chosen the best response.0
I 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.
 2 years ago

estudier Group TitleBest ResponseYou've already chosen the best response.1
I got so far (for roots a,a and c) 3a +c = 2 and a^2 c = 24 U get that?
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.0
w8 , what's c ?
 2 years ago

estudier Group TitleBest ResponseYou've already chosen the best response.1
I don't mean understand, I mean u calculated same?
 2 years ago

estudier Group TitleBest ResponseYou've already chosen the best response.1
I said for roots, a,a and c
 2 years ago

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

estudier Group TitleBest ResponseYou've already chosen the best response.1
There is similar (not same) formula like Vieta for cubic as for quadratic....
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.0
What's Vieta ?
 2 years ago

estudier Group TitleBest ResponseYou've already chosen the best response.1
Formulae for sum and product of roots of quadratic.
 2 years ago

jimmywhoaaw Group TitleBest ResponseYou've already chosen the best response.0
Let 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
 2 years ago

Mimi_x3 Group TitleBest ResponseYou've already chosen the best response.0
thank you (:
 2 years ago
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