# Calculating sin and cos functions

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Mohsin Shah on 29 May 2011
Commented: Walter Roberson on 18 Dec 2021
Hello, i calculated the value of sin(45) in Matlab, the result was sin(45)=0.8509 and for cosin i got cos(45)= 0.5253. From general mathematics we know that sin(45)=cos(45) then why Matlab is giving different results??

Paulo Silva on 29 May 2011
Those functions work in radians not degrees, try this
cosd(45)
sind(45)
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Abdullah Amin on 18 Dec 2021
y=sin(-75) then y variable should carry value
+1 -1 +75 -75
Walter Roberson on 18 Dec 2021
It is not clear to me why sin() of a scalar should result in a vector of length 4 ? Or why those particular values should be output ?

### More Answers (1)

bym on 29 May 2011
sin() & cos() arguments are in radians. If you want degrees use
sind() cosd()
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Muhammed Çelik on 20 Apr 2020
or, you can do like this sin(degree*pi/180)
Steven Lord on 20 Apr 2020
If you're going to convert degrees to radians or vice versa, use the deg2rad or rad2deg functions moved from Mapping Toolbox to MATLAB in release R2015b rather than the "magic number" of pi/180.

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