factor theorem
Use the Factor Theorem to determine whether the first polynomial is a factor of the second polynomial. x - 5; 3x2 + 5x + 50
if yes, that would mean that ... is a zero. just check if ... is indeed a zero.
3(0)^2+5(0)+50 0+0+50 50 so no?
don't replace \(x\) by \(0\). replace \(x\) by \(5\)
in any case, \(5\) cannot be a zero of \( 3x^2 + 5x + 50 \) because all the coefficients are positive
okay... so 3(5)^2+5(5)+50 75+25+50=150
the factor theorem basically says if (x -5) is a factor then x = 5 is a zero so you need to find f(5) if f(5) = 0 then you know (x -5) is a factor
we arnt trying to find 0's though....
that is clear right? if all the coefficients are positive, and you replace \(x\) by a positive number, then everything is positive, so it cannot be zero zeros mean \[f(x)=0\] not \(f(0)\)
for example the zeros of \(x^2-4\) are \(2\) and \(-2\) not \(0^2-4=-4\)
in any event \( f(x)=3x^2 + 5x + 50\) lives entirely above the \(x\) axis and has no zeros does not factor with real numbers
according to the thm: (x-5) is a factor of the polynomial IFF 5 is a zero of the polynomial. 5 is not a zero => x-5 is not a factor of the polynomial.
ok... so given a polynomial e.g \[y = x^2 + 5x + 6 \] then it factors to \[y = (x + 2)(x + 3)\] to find the values of x that may y = 0 you need to solve \[x + 2 = 0... and.... x + 3 = 0\] so the solutions are x = -2, and x = -3 substitute these values into the original equation and you'll find f(-2) = 0....... and f (-3) = 0 so therefore (x +2) and (x + 3) are factors...
lol okay thanks you guys
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