Question

y-int??? f(x)=3x^3-17x^2+18x+8

Answer 1

y=8 is y intercept

Answer 2

set x=0
and solve for y

Answer 3

(0,8) y intercept

Answer 4

3x^3-17x^2+18x+8=0

Answer 5

how do u find the x-int??

Answer 6

yes thats how yet set 3x^3-17x^2+18x+8=0
solve solve for x

Answer 7

x=2 works

Answer 8

i have stuck with x-int i dont know why i cant find it...

Answer 9

(x-4)(x-2)(3x+1)

Answer 10

2| 3 -17 18 8
| 6 -22 -8
-----------------
3 -11 -4 | 0

Answer 11

:)..how did u get x=2??? it's right but i wonder know why??

Answer 12

you can guess using the rational root theorem... but there's a lot of guesses you can make for the root. It's somewhat trial and error unless you use calculus to determine the interval of one of the roots.

Answer 13

3x^2-11x-4=0
\[x=\frac{11 \pm \sqrt{121-4(3)(-4)}}{6}=\frac{11 \pm \sqrt{121+48}}{6}=\frac{11 \pm \sqrt{169}}{6}=\frac{11 \pm 13}{6}\]

Answer 14

right its a guessing thing

Answer 15

i mean not really guessing you have a set of rational numbers and you can do trial and error i just chose 2 and it worked

Answer 16

all the rational roots would be ±1, ±2, ±4, ±8, ±1/3, ±2/3, ±4/3, ±8/3.

Answer 17

you look at factors of 8 and you look at factors or 3
and you also ook at factors of 8/3

Answer 18

and he listed them all

Answer 19

so we see we have two rational answers using the quad formula they should be in his list

Answer 20

we have x=24/6=4 and x=-2/6=-1/3

Answer 21

ok... thanks for everyone helping me!!!!