Question

Use decimal search to find the root correct to 2 decimal places.

\[f(x)=x^5 - 5x +6\]

Answer 1

hi @order

Answer 2

Hello. Do you know if you can help?

Answer 3

i only know algebra 1 :(

Answer 4

There are number of things that you can do for solving this one,Bisection method or Newton Raphson method or even just Mathematica solve function ;-)

Answer 5

Can you show the Newton Raphson method? So that I can work out the others by myself? I love looking at steps... it helps me to understand.

Answer 6

whats decimal search?

Answer 7

The basic idea of Newton raphson is described here http://en.wikipedia.org/wiki/Newton's_method

Note, the more the iteration the precise is your answer.

Answer 8

It describes how you can use the sign-change rule to find a sequence of approximations to the root, improving accuracy by 1 decimal place at a time.

Answer 9

@order the newton method is what i tried showing you on the earlier post

Answer 10

Yes, I know... but this is for a more precise method.

Answer 11

To get to 2 decimal places.

Answer 12

same thing, keep going until the x_value stops changing

Answer 13

Ok... But this is a very long method if I were to find up to 5 decimals! But that's math :/

Answer 14

hint, use a spreadsheet if you can

Answer 15

Method is bisection requires two values, it just utilizing the basic concept that sign changes at roots. So if f(a) and f(b) have different sign it means we have a at-least one root between a and b.

Answer 16

Thanks

Answer 17

For this particular equation there is one real root at x = -1.70811