converting radian to degrees

[hollerback1]

Hi, I'm having trouble rounding the degrees and minutes

For example:

2.2 = 126deg.0'

3.7 = 161deg.30'

165deg.35'5.24"

I'm not sure if these are right :?


How would you round it correctly?

I'm not sure what to round when minutes is above 30? or below 30?

Thanks.

 

[tkhunny]

\(\displaystyle 2.2*\frac{180}{\pi} = 126.0507149\)

126.0507149º = 126º + 0.0507149º

0.0507149º = 0.057149*60 min = 3.042894 min

3.042894 min = 3 min + 0.042894 min

0.042894 min = 0.042894*60 sec = 2.57364 sec

Checking

2.57364/60 = 0.042894
3.042894/60 = 0.0507149
126.0507149*pi/180 = 2.19999999999 -- Close enough.

 

[wjm11]

TK is too quick for me! But similarly:

Hi, I'm having trouble rounding the degrees and minutes

For example:

2.2 = 126deg.0'

The problem directions should, hopefully, include the desired accuracy in the answer. For example, the directions (or instructor) might specify to give answers the nearest degree, or minute, or second, or tenth of a second:

Consider that 2.2 radians is approximately equal to 126.0507149 degrees.

Rounded to the nearest degree: 126
Rounded to the nearest minute: 126 degrees, 3 minutes
Rounded to the nearest second: 126 degrees, 3 minutes, 3 seconds
Rounded to the nearest tenth of a second: 126 degrees, 3 minutes, 2.6 seconds

It all depends on what’s asked for.

 

[hollerback1]

Oh, I see thank you so much, but I'm a bit confused because my teacher said something about rounding up wen its above 30? & rounding down if it's below 30? Or it's the other way around? :?: :?


Thanks again.

 

[tkhunny]

If your teacher has rules, follow them.

If it should be rounded to minutes, then yes, 30 sec or more goes up. 29 seconds or less goes down.

Neither example included any rounding rules.

Oh, and let's forget the silly concept of rounding up or rounding down. Rounding increases or decreases as appropriate according to your rules. What often gets called "rounding down" is really called "truncating".