An angle is given to one significant figure as 7 degrees

1. Sep 15, 2005

An angle is given to one significant figure as 7 degrees, meaning thats its value is between 6.5 degrees and 7.5 degrees. Find the corresponding range of possible values of the cosine of the angle. Is this a case in which there are more significant figures in the result than in the input data?

I know the answer to the last question is yes. When I type in $$cos(7)$$ I get 0.9925461516. Would I round this up to 1 degree, thus its range of values is between 0.5 degrees and 1.5 degrees?

thanks

Last edited by a moderator: Jan 3, 2014
2. Sep 16, 2005

whozum

The angle is between 6.5 and 7.5 degrees, but you aren't sure. It's asking you to find what range the cosine of that angle lies in.

3. Sep 16, 2005

HallsofIvy

Staff Emeritus
The largest the angle can be is 7.5 degrees. What is the cosine of 7.5 degrees?

The smallest the angle can be is 6.5 degrees. What is the cosine of 6.5 degrees?

Now, what do YOU think the possible range for cosine is? You may notice that some of the digits in the two answers are the same. What would be a good way of reporting a single number to represent that range?