This video gives an explanation of how to work with difficult iteration type questions, sometimes called iterative formula. It’s extremely wordy … but should be absolutely fine once you get the general idea. I’ll post some additional videos, with similar questions, in the next few days.

The question is aimed at GCSE maths grade 7+ calculator paper.

(a) Complete the table of values for y = x^3-5x-8

(b) On the grid, draw the graph of y = x^3-5x-8

(c) Show that when f(x) = 0, the equation f(x) = x^3-5x-8 can be rearranged to give x= ∛(5x+8)

(d) Use the iterative formula x_(n+1)= ∛(〖5x〗_n+8) to find the real root of f(x) correct to 3 decimal places.

Watch on YouTube

How to work with iteration part 3

I hope it becomes a little clearer as you work through the quick test videos, before moving on to the higher levels. They do take a bit of a leap forward, although should be OK if you have viewed the earlier ones.

If you would like to find out more try these!

How to work with iteration part 2

Please do leave a comment below if you are not sure. Alternately you can view my YouTube channel and leave a comment there – I’ll always try to respond as quickly as possible.

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