Iterations to 1 Decimal Places
Maths: Edexcel A Level Pure Maths, topic 9.1.2
Approximate Solutions
Find the solution of x³ - 3x + 1 to 1 decimal place:
We know that the solution is between 1 and 2 from before
Sub in a trial solution x = 1.5
This gives -0.125
-0.125 is less than 0 so is below our target
Sub in our second guess, x = 1.54
This gives 0.0323
0.0323 is more than 0 so is above our target
Approximation of x
- x = 1.5 gives a result below 0
- x = 1.54 gives a result above 0
- Therefore the x value which gives exactly 0 must be in between 1.5 and 1.54.
To 1 decimal place
- All values between 1.5 and 1.54 round to 1.5 to 1 d.p.
- This is our solution.
Test yourself on Iterations to 1 Decimal Places
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