Math, asked by khush7254, 1 year ago

Sin(40+theta)cos(10+theta)-cos(40+theta)sin(10+theta)=1/2

Answers

Answered by mysticd
160
Hi ,

we know that ,
************************************************

sin A cos B - sin B cos A = sin ( A - B )

*************************************************

let A = 40 + θ,

B = 10 + θ,

According to the problem ,

sin( 40 + θ )cos( 10 + θ ) - sin( 10 + θ)cos( 40+θ)

= sin A cos B - sin B cos A

= sin ( A - B )

put A and B

= sin [ 40 + θ - ( 10 + θ ) ]

= sin ( 40 + θ - 10 - θ )

= sin (30)

= 1/2

i hope this will useful to you.

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Answered by pankaj12je
43
Hi friend,
given is of the form sinAcosB-cosAsinB=sin(A-B)
here A=40+θ, B=10+θ
So sin(40+θ-10-θ)
    =sin30=1/2
Therefore LHS =RHS

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