Disc Math Logic statements (Homework check)

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The discussion focuses on the evaluation of logical statements in discrete mathematics. The first statement (d) is critiqued for incorrectly interpreting the quantifiers, as it suggests that for every faculty member, there exists a student who has not asked them a question, which differs from the intended meaning. The need to swap the quantifiers in statement d is emphasized for accuracy. The other statements (e and f) are confirmed to be correct. Overall, the discussion highlights the importance of understanding quantifier placement in logical expressions.
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My solution
d. \forallx\existsy(F(x)^S(y) → \negA(y,x))
e. \existsx\forally(F(x)^S(y) → \negA(y,x))
f.\existsx\forally(S(x)^F(y) → A(x,y))
 

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Miike012 said:
My solution
d. \forall x \exists y(F(x)^S(y) → \neg A(y,x))
e. \exists x \forall y(F(x)^S(y) → \neg A(y,x))
f.\exists x \forall y(S(x)^F(y) → A(x,y))

For d: You have "for every faculty member, there is a student who has not asked a question of that faculty member". That's not equivalent to "some student has not asked a question of any faculty member", because in the first it might not be the same student in each case. You need to swap the quantifiers.

The others appear to be correct.
 
I tried to combine those 2 formulas but it didn't work. I tried using another case where there are 2 red balls and 2 blue balls only so when combining the formula I got ##\frac{(4-1)!}{2!2!}=\frac{3}{2}## which does not make sense. Is there any formula to calculate cyclic permutation of identical objects or I have to do it by listing all the possibilities? Thanks
Since ##px^9+q## is the factor, then ##x^9=\frac{-q}{p}## will be one of the roots. Let ##f(x)=27x^{18}+bx^9+70##, then: $$27\left(\frac{-q}{p}\right)^2+b\left(\frac{-q}{p}\right)+70=0$$ $$b=27 \frac{q}{p}+70 \frac{p}{q}$$ $$b=\frac{27q^2+70p^2}{pq}$$ From this expression, it looks like there is no greatest value of ##b## because increasing the value of ##p## and ##q## will also increase the value of ##b##. How to find the greatest value of ##b##? Thanks

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