How do you verify the intermediate value theorem over the interval [0,3], and find the c that is guaranteed by the theorem such that f(c)=0 where f(x)=x^2-6x+8?

1 Answer
Nov 1, 2017

Intermediate Value theorem is verified so, there exist c in [0,3]
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such that f (c)=0
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c=2

Explanation:

f is continuous over [0,3] and
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f (0)=0^2-6 (0)+8=8
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f (3)=3^2-6 (3)+8 = 9-18+8=-1
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Intermediate Value theorem is defined over [0,3] for f (x)
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Because
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f is continuous over [0,3] and f (3)< f (c) < f (0)
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then there exist 0 < c < 3 such that f (c)=0" "
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c = ??
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f (c)=0
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rArrc^2 -6c +8 = 0
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rArr c^2 -6c +8 + 9 -9 =0
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rArr c^2 - 6c +9 -9 +8 = 0
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rArr (c^2 -2 (3)c +3^2)-9+8=0
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Factorization in the previous step is determined by applying :
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(a-b)^2=a^2-2ab+b^2
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rArr (c-3)^2-1=0
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rArr (c-3)^2-1^2=0
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Factorization here is determined by applying the followingbidentiyy:
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a^2-b^2=(a-b)(a+b)
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rArr ((c-3)-1)((c-3)+1)=0
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rArr (c-4)(c-2)=0
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rArrc-4=0rArrc=4" "Rejected since" "4!in [0,3]
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Or
rArrc-2=0rArrc=2" "Accepted since" "2in [0,3]