Question

Let f(x) = x^5 -6x +5
(i) complete the table (done already)
(ii) It is known that the equation f(x)=0 has only one root greater than 1. Using (i) and the method of bisection, find this root correct to 3 decimal places

Answer 1

Table for (i)

Answer 2

To specify the problem, I don't know how to begin with doing (ii).

Answer 3

at x=1.05 and x=1.1, f has opposite signs so the root must be in the interval [1.05, 1.1].

so now take the midpoint of this interval to split up the intrval into two intervals. now check do the same with these two sub intervals to check where the root is...

this is as far as I can remember doing the bisection method... sorry...

Answer 4

could we use newton's method?

Answer 5

Sorry, but how can i do it, can you demonstrate a little?

Answer 6

As long as you've used method of bisection, i think that's okay. But another problem is i don't know what bisection method is :S

Answer 7

it's basically if you know a root is in some interval, take the midpoint of that interval so now you have two sub intervals. check the endpoints of these subintervals, if the sign of f is opposite at the enpoints of a particular subinterval, then the root must be in that subinterval. the process repeats....

Answer 8

so do I :))

Answer 9

haven't tackled that yet either