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# Solving Question watch

1. This is probably really stupid, but how do you solve solve y^3+3y-3=0?

Thanks
2. (Original post by bertiejess)
This is probably really stupid, but how do you solve solve y^3+3y-3=0?

Thanks
What level of mathematics do you currently have?

If you are just looking for the real root, you could use a numerical method such as looking for a change of sign or using iteration.

If you want to solve it exactly, you could notice that there is no y^2 term. This is called a depressed cubic and Google will show you how to deal with it.
3. (Original post by Mr M)
What level of mathematics do you currently have?

If you are just looking for the real root, you could use a numerical method such as looking for a change of sign or using iteration.

If you want to solve it exactly, you could notice that there is no y^2 term. This is called a depressed cubic and Google will show you how to deal with it.
this is in chapter 4 of C3
4. (Original post by bertiejess)
this is in chapter 4 of C3
Use Iteration. Chapter 4 is numerical methods if I remember correctly.
5. (Original post by Mr M)
What level of mathematics do you currently have?

If you are just looking for the real root, you could use a numerical method such as looking for a change of sign or using iteration.

If you want to solve it exactly, you could notice that there is no y^2 term. This is called a depressed cubic and Google will show you how to deal with it.
what is a depressed cubic Mr M?
6. (Original post by bertiejess)
this is in chapter 4 of C3
Ok

Find f(0) and f(1) - note there is a sign change so there is a root between 0 and 1.

Rearrange into y = something.

Now use the right hand side as an iterative formula.

1 =

(3 - ANS^3)/3 =

Press = a lot

This will converge to the real root
7. (Original post by Prokaryotic_crap)
what is a depressed cubic Mr M?
A really fed up polynomial?

http://fermatslasttheorem.blogspot.c...sed-cubic.html

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