# c3 question....Watch

#1
Hey, I am stuck on this question:

Find an equation of the form ax^3 + bx + c = 0, where a, b and c are integers, which has t as a root.

For the previous part of the equation I found t= 2.877.

Thanks for any help!
0
9 years ago
#2
Definitely need the previous part of the question.
0
#3
The sequence is defined by:

x(n+1)= cube root(31-2.5 x (n))

x1= 3

it converges at t.

i found t= 2.877
0
9 years ago
#4
How do you get an iterative formula ?

You just re-arrange the equation - so just do the reverse.

Rearrange the equation to remove the cube root.

x^3 = 31 - 2.5x

Rearrange this with integer coefficients of x and that's the answer.
0
X

new posts
Latest
My Feed

### Oops, nobody has postedin the last few hours.

Why not re-start the conversation?

see more

### See more of what you like onThe Student Room

You can personalise what you see on TSR. Tell us a little about yourself to get started.

### University open days

• Cardiff Metropolitan University
Sat, 27 Apr '19
• University of East Anglia
Could you inspire the next generation? Find out more about becoming a Primary teacher with UEA… Postgraduate
Sat, 27 Apr '19
• Anglia Ruskin University
Health, Education, Medicine and Social Care; Arts, Humanities and Social Sciences; Business and Law; Science and Engineering Undergraduate
Sat, 27 Apr '19

### Poll

Join the discussion

#### Have you registered to vote?

Yes! (553)
37.82%
No - but I will (115)
7.87%
No - I don't want to (103)
7.05%
No - I can't vote (<18, not in UK, etc) (691)
47.26%