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![[Post New]](/templates/default/images/icon_minipost_new.gif) 7 Apr 2008 03:22:01 IST
Accepted Answer [?]
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2 8 cos 3 @ sin 5 @
sin 5 @ can be written as sin 3 @ sin 2 @
it is = 2 8 cos 3 @ sin 3 @ sin 2 @
Now 2 sin @ cos @ = sin 2 @
So 2 3 sin 3 @ cos 3 @ = sin 3 2 @
Thus it can be written as 2 5 sin 3 2@ . sin 2 @
= 2 sin 2 @ . 2 4 sin 3 2@
[ 2 sin 2 @ = 1 - cos 2 @ ]
So 4 ( 1 - cos 2 @ ) . 4 sin 3 2@
= 4 ( 1- cos 2 @) .[ 3 sin 2 @ - sin 6@ ]
= 4 [ 3 sin 2 @ - 3 sin 2 @ cos 2 @ - sin 6@ + sin 6@ cos 2@ ]
= 12 sin 2 @ - 6 sin 4@ - 4 sin 6@ + 4 sin 6@ cos 2 @
= 12 sin 2@ - 6 sin 4@ - 4 sin 6@ + 2 ( sin 8@ + sin 4@)
= 12 sin 2@ - 6 sin 4@ - 4 sin 6@ + 2 sin 8@ + 2 sin 4@
= 12 sin 2@ - 4 sin 4@ - 4 sin 6@ + 2 sin 8@
Hence we get a = 12 , b = -4 , c = -4 , d = 12
So answers :
A : r , B : p , C : p , D : q
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All that is gold does not glitter
Not all who wander are lost
The old that is strong does not wither,
Deep roots are not reached by frost.
From ashes a fire shall be woken
From shadows a light shall spring
Renewed shall be blade that's broken
The crown less again shall be king. |
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