Convert #5^@ 37^'30^('') #into radians?

1 Answer
Jun 16, 2018

#673/21600 pi " radians"larr color(red)("Exact answer")#

#color(white)("d")#

#x=0.0979" radians" color(red)(larr" Approx answer")#
#color(white)("dddddddddddddddddd.d")#rounded to 4 dec places

Explanation:

Measuring in degrees #37' = 36/60 = 3/5# degrees

and #30''=cancel(30)^1/(cancel(60)^2xx60)=1/(120# degrees

Therefor #5^ocolor(white)(.)37'color(white)(.)30''=5+3/5+1/120=5 73/120 = 673/120# degrees

Used fractions because the decimal equivalent has a repeating value. If I use decimals I may introduced a rounding error. Also #pi# is an irrational number so converting to decimal will have a rounding error.
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Known: #1/2# a circle has #pi" radians "=180^o#

When conducting conversions a good way of thinking about it is to use ratio but in fraction format.

Let the unknown count of radians be #x# giving

#("required radians")/("radians in "1/2" a circle") -=( 673/120)/(180)#

#color(white)("dddddddd")(x)/(pi)color(white)("dddddddd") -=( 673/120)/(180)#

Multiply both sides by #pi#

#x=( 673/120)/180xxpi #

#x= 673/120xx1/180xxpi#

#x=673/21600 pi larr color(red)("Exact answer")#

#x=0.097883882.... #

#x=0.0979" radians" color(red)(larr" Approximate answer")#