Question

Can someone solve: y= x^3 + 3x^2 - 9x +1? In class we use 5 steps:

1. y'
2. factor to get x
3. y''
4. factor to get x
5. x = 0, y=0

Not sure what Im doing

Answer 1

\[y' = 3x^2 + 6x - 9\]

Answer 2

yes right

Answer 3

but what is that you want us to do??????Peser

Answer 4

(3x - 3)(x +3)

Answer 5

why are we doing it?

Answer 6

x = 1 ,-3 maybe maxima and minima

Answer 7

yes, it says maxima and minima

Answer 8

y" = 6x +6
x=-1

Answer 9

right... ishaan right

Answer 10

sorry, im in a 4 wk course, teach isnt very specific on a lot of things

Answer 11

We have to graph this on our calculator

Answer 12

well you got maxima for the points 1 , -3

Answer 13

http://www.wolframalpha.com/input/?i=y%3D+x^3+%2B+3x^2+-+9x+%2B1

Answer 14

maxima for -3 and minima for1

Answer 15

it says I need to find the intercepts as well?

Answer 16

ok just solve by putting y=0 and x=0

Answer 17

when x = 0we get y=1

Answer 18

ah! duh me. Thank you!!

Answer 19

similarly with x put y=0 and get x intercepts

Answer 20

u rule. thanks again. :)

Answer 21

haha :D thanks