What is the third–degree polynomial function such that f(0) = –12 and whose zeros are 1, 2, and 3? f(x) = 2x3 + 12x2 – 22x – 12 f(x) = 2x3 – 12x2 + 22x – 12 f(x) = 4x3 – 24x2 + 22x – 24 f(x) = 4x3 + 24x2 – 44x – 24 What is the third–degree polynomial function such that f(0) = –12 and whose zeros are 1, 2, and 3? f(x) = 2x3 + 12x2 – 22x – 12 f(x) = 2x3 – 12x2 + 22x – 12 f(x) = 4x3 – 24x2 + 22x – 24 f(x) = 4x3 + 24x2 – 44x – 24 @Mathematics
Some help?
the factored form of a third degree polynomial looks like f(x) = k(x-a)(x-b)(x-c) f(0)=-12 that means when x =0 f(x)=-12 and a=1, b=2, c=3 substituting in equation 1 f(0)= k(0-1)(0-2)(0-3) f(0) = -6k therefore -12=-6k k=2 so the polynomial is f(x)=2(x-1)(x-2)(x-3)
expand it lol
The second choice is the right one btw:)
haha k, how did you get -6?
u know that f(0) = -12 right?
yes
and f(x)=k(x-a)(x-b)(x-c) so if u substitute x=0 here f(0)=k(0-a)(0-b)(0-c) f(0) = k(-a)(-b)(-c) a, b and c are the zeros of the polynomial so a=1 and b=2 and c=3 substituting these values in f(0) u get f(0) = k(-1)(-2)(-3) f(0)= k * -6 and we know that f(0)=-12 so -6k=-12
Oh is this a theorem? or no?
all third degree polynomials look like f(x)=k(x-a)(x-b)(x-c) where k is any constant and a,b,c are zeros of polynomial
Oh ok, man I have to find that in my lessons, I dont even know if it mentioned it haha.
hehe, it can be found using other methods, this is the easiest
Oh would you mind telling me the other methods? sorry for all the questions haha I just want to have it down packed
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