Question

Does anyone know to solve depressed cubic equations

Answer 1

sing them a happy song

but in all seriousness, ye, what do you need help with

Answer 2

lol , solving a general depressed one

Answer 3

show us your problem

Answer 4

Like solving

x^3 + 3x + 4 =0

Answer 5

Which has the missing x^2 term in the cubic polynomial is called depressed

Answer 6

this is true.
so this is of the form:
x^3 + Ax = B
we have to find two numbers, f and g, so that:
$$A = 3fg \\ f^3-g^3 = B$$
so:
3 = 3fg
f^3-g^3 = -4
do you know any numbers that satisfy this?

Answer 7

That's a problem i just created , it maynot have perfect whole no factors , but i seem to get a idea thanks

Answer 8

i tried to simplify it as much as possible, lol. np

Answer 9

well i got it here
http://2000clicks.com/mathhelp/FactoringCubic1.aspx

Answer 10

Which grade are u in?

Answer 11

you figured out how to solve these ? :)

Answer 12

yes cardano's method

Answer 13

yes that method is there, but can u apply it really and get all the way to having solutions ?

Answer 14

you will need to take complex roots on the way...

Answer 15

try to solve ur cubic and see

Answer 16

okay :)

Answer 17

I will solve it after i complete my hw :)

Answer 18

sure, whenever u have time... ive never seen anyone solving a cubic manually before lol

Answer 19

lol , i am going to use a calculator otherwise i will die

Answer 20

but ur equation can be solved easily w/o using cardon's method as -1 is one solution

Answer 21

simply do synthetic division and use quadratic formula to solve the remaining quadratic

Answer 22

i heard there is a way to solve septic equations (i am not going to ) but the wikipedia hardly mentions it

Answer 23

not all septics are solvable

Answer 24

may be only few can be solvable

Answer 25

It is a proven fact that there is no algebraic method for solving 5th degree and above polynomials

Answer 26

you can solve all 4th degree polynomials also^

Answer 27

yes quartic

Answer 28

anyways do ur hw for now lol, we can get back to these later :)

Answer 29

Yes!

Answer 30

i just wanted to ask you out of curiosity how did came to know about OS

Answer 31

haha by clicking a link in electromagnetism course page :

http://ocw.mit.edu/courses/physics/8-02-electricity-and-magnetism-spring-2002/video-lectures/

Answer 32

wbu ?

Answer 33

I was solving a 3d trigo problem and i posted in google and i clicked the first link and i was into the OS world
@wio helped me (my first question)

Answer 34

interesting!

Answer 35

wow ! @wio went ghost for last few days.. not seeing him much these days ;=;

Answer 36

Yes, He is not there
He is a trigonometry specialist , he mostly solves trig related problems