Given cos 40=m and sin 10=n,can u please express sin 50 in terms of m and n?

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Answer 1 · 2017-07-08T10:27:40

#sin50=sin(40+10)#

#=sin40cos10+cos40sin10#

#=sqrt((1-m^2)) * sqrt((1-n^2))+mn#

Use

#sin(A+B)= sinAcosB+cosAsinB#

and

#(cos40)^2+(sin40)^2=1#

or

#(sin40)^2=1-(cos40)^2#

or

#sin40=sqrt([1-(cos40)^2])#

or

#sin40=sqrt((1-m^2))#

Similarly,

#cos40=sqrt((1-n^2))#