Question

Identify one actual root

f(x)=7x^3-5x^2-63x+45

Answer 1

did you try trial and error method ?

Answer 2

There's 2 actual roots for this

Answer 3

Sam how do I find them

Answer 4

I would try factoring by grouping if you want to completely factor.

Answer 5

\[7x^3-5x^2-63x+45\]\[x^2(7x-5) -9(7x-5)\]\[(x^2-9)(7x-5)\]\[(x-3)(x+3)(7x-5)\]From here, it's easy to see what the three roots are.

Answer 6

I thought there was only one negative root mmmm

Answer 7

Or use trial an error (x+3) is one of the factor,
then do long division and found 7x^2-26x+15
(x+3)(7x^2-26x+15)
(x+3)(x−3)(7x−5)

Answer 8

There is only one negative root. \(x=-3\). The others are positive.

Answer 9

ok makes since but does that count as the actual root?

Answer 10

or is it diffrent?

Answer 11

\(x=-3\) counts as an actual root.

Answer 12

whooo hoo thank you