Rounding in Inequality

Example 1: 2015 P1 8ii

2015 P1 Q8



Examiner’s report 

exam report

Example 2: 2015 P1 2ii

2015 P1 Q2

Examiner’s report

exact round


Graphical approach will yield  x> 1.732. Notice Cambridge answer  is not rounded to x>1.74 to satisfy the non-rounded inequality but rounded to 3 s.f.


Considering example 1 and example 2, we conclude that in real life applications questions, when rounding off your answer to 3 s.f, round off such that the rounded off answer still satisfies the non-rounded off inequality.

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