Question on rounding!!!

I am doing this exam question on the trapezium rule and it says to find the area under the graph of (sinx)^2 and give your answer to 3 decimal places. I used the trapezium rule and just substituted the exact values of (sinx)^2 for each value of x into my calculator and rounded at the end and got 0.433. However someone else did it by rounding each value of (sinx)^2 to 3d.p. as they went along and got 0.434. When should I round or would a mark scheme accept both answers?

My advice would be to only round your final answer. I just use the values which are given in the table and I know nothing will go wrong from there (as long as you put it in the calculator correctly). To answer your question I think a mark scheme would accept both answers but I think 0.433 is more accurate to 3d.p. Hopefully that helped.

Premature rounding during interim calculations is the best way of getting an incorrect answer. Only round at the end, and make use of the ANS key during any interim steps rather than round or truncate the decimal.

I am doing this exam question on the trapezium rule and it says to find the area under the graph of (sinx)^2 and give your answer to 3 decimal places. I used the trapezium rule and just substituted the exact values of (sinx)^2 for each value of x into my calculator and rounded at the end and got 0.433. However someone else did it by rounding each value of (sinx)^2 to 3d.p. as they went along and got 0.434. When should I round or would a mark scheme accept both answers?

Premature rounding during interim calculations is the best way of getting an incorrect answer. Only round at the end, and make use of the ANS key during any interim steps rather than round or truncate the decimal.

Welcome back!

Thank you 🙂. How are you?

In exam season! Did a last minute revision session this morning [a few students with last minute panics] for this afternoon's paper ..
What about you?

Same - I had some panicky tutees who needed calming down a bit (overbearing parents are the main problem with one of them, frankly). A girl who'd worked herself up into a tizz because she couldn't do 'that question' on a Edexcel past paper involving three circles and equilateral trianges and who, as a consequence of that, was convinced she's going to fail (she'll get a 9 I think). Usual things...
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Where do I start? The new search is rubbish ...
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