cos21-sin83=-2sin14sin7
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Dear Friend ♡,
This proof is done by Trigonometric formula of
Cos x - Cos y = - 2 Sin (x+y)/2 × Sin (x-y)/2
Proof :
LHS
= Cos 21 - Sin 83
= Cos 21 - Sin ( 90 - 7 )
= Cos 21 - Cos 7
》 Now use the Formula given above.
Cos 21 - Cos 7 = - 2 Sin ( 21 + 7)/2 × Sin ( 21- 7 )/2 = - 2 Sin 28/2 × Sin 14/2 = - 2 Sin 14 × Sin 7
= 《《RHS》》
☆ Hence proved !!!! ☆
This proof is done by Trigonometric formula of
Cos x - Cos y = - 2 Sin (x+y)/2 × Sin (x-y)/2
Proof :
LHS
= Cos 21 - Sin 83
= Cos 21 - Sin ( 90 - 7 )
= Cos 21 - Cos 7
》 Now use the Formula given above.
Cos 21 - Cos 7 = - 2 Sin ( 21 + 7)/2 × Sin ( 21- 7 )/2 = - 2 Sin 28/2 × Sin 14/2 = - 2 Sin 14 × Sin 7
= 《《RHS》》
☆ Hence proved !!!! ☆
BrainlyHulk:
is your doubt complete
I d k his doubt but my doubt is finished.... Nice answer♥
*i d k his doubt is finished or not
thank you bro
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