Significant Figures (PHYSICS 'O')
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Originally posted by Lee012lee:
Ya lor, we always have this problem ie if we give an intermediate value for the answer for part (a) correct to 3 sig fig and this intermediate is required for the calculation for the answer for part (b), should we substitute the corrected intermediate value or the exact intermediate value in the calculation for the answer for part (b) huh ?
U can use the exact intermediate value for part b if its not difficult to fish out from the calculator's memory....otherwise...using 4 s.f(or above if U are really kiasu)will do...if ur final answer is to be in 3 s.f...Remember its not the extra digits U put in that shows ur understanding.
Simple example:
calculate cos (pi/12) x 20.
Using exact value :
cos (pi/12) x 20
=cos (0.26179938779) x 20
=19.3 radians (3 s.f)
Using 4 s.f in intermediate value :
cos (pi/12) * 20
= cos (0.2618) * 20
=19.3 radians (3 s.f)
end of the day the final answer will not vary by a lot....what the examiners want to know if whether U know ur s.f....not how many digits U can squeeze into the width of an A4-sized exam paper.
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Originally posted by MyNameisNas:
can i write in fraction form???
Eg
3.33333333333333333333.. as 3r1r3??
Fraction form is more accurate.
yes U can....and yes...fraction form is more accurate...but what for?
The process of converting to fraction form negates the benefits of its accuracy....Not that it will have a big impact on ur final answer.
My suggestion is to stick with the decimals and know ur s.f.
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Originally posted by sinicker:
wah my method no one follow ar?
ur method is good if U know the calculator well enough...