Same type of question
okay so for part I I got +-1,+-,2,+-3,+-4,+-6,+-12
then for part II i got 1
am i on the right track so far?
the root 1 does not produce a remainder of 0 after synthetic division so you will have to ry another root
2
not quite, check your calculations again if you plug in the root into the equation it should equal 0
to speed this process up you can use a calculator to start plugging in x values and see which ones give you 0, starting with 1 or -1, then 2 and -2, etc. until you get 0
silly if you're reading this is there an easier way to narrow down the possible roots w/o using calculus
okay so zero for part II
@sillybilly123
0 is not a possible root (it is not in your list of rational roots)
\(\color{#0cbb34}{\text{Originally Posted by}}\) @zarkam21 okay so for part I I got +-1,+-,2,+-3,+-4,+-6,+-12 \(\color{#0cbb34}{\text{End of Quote}}\) ^ your root must be one of these
4
when you plug in x = 4, your result is not 0 so keep trying
i got it
its 3
good for part III) divide the function by (x-3) and write the resulting function
x^3+4x^2+6x+4
awesome, then for part IV try to find another root by testing the possible roots from part I
good, now try testing these roots to see if you can find another solution
so just substitute for x right
yes
into the cubic function right not the original
yes (technically both will work but cubic is easier)
I'm getting 15,40,85
Am i on the right track
what did you do to obtain these values?
oh i have to set them equal to zero
if you are plugging in roots, keep going until the result is 0
oh okY
-2?
good, so -2 is the other root so that's your answer for IV
OKAY SO for part V it would just be x=-1,+-i,-2
part V is not in the original screenshot
PArtV use the quadratic formula to find the final 2 roots
after you divide the cubic polynomial by (x+2) what polynomial do you get?
x^2+2x+2
good, now apply the quadratic formula to get the last two roots
x=-1+i
good but don't forget the other one x = -1 - i (remember the quadratic formula has a +/- sign) and that's it
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