Cos(38.1) = 0.7869350 What is the answer expressed to the correct number of significant figures. How do you know what the significant figures here?
1 Answer
Sep 12, 2015
Explanation:
Assume that the measured angle is 38.1° ± 0.1°.
The calculated values of the cosines are
The rule is that the values should differ only in one digit.
To 3 digits after the decimal place, the values become
These differ only in the third digit after the decimal place, so the cosine of the measured angle 38.1° has three significant figures.
The cosine of the mathematical (exact) angle 38.1 ° has an infinite number of significant figures.