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Question : 21 of 160
Marks:
+1,
-0
Solution:
Let's consider the expression as,
x=sin4‌+sin4‌+sin4‌+sin4‌+sin4‌+sin4‌+sin4‌ So
x=[sin4‌+sin4‌+sin4‌+sin4‌]+[] =[| sin4‌+sin4‌+ |
| cos4(‌−‌)+cos4(‌−‌) |
]+[| sin4‌+sin4‌ |
| +sin4(‌+‌) |
] =[sin4‌+sin4‌+cos4‌+cos4‌]+[| sin4‌+sin4‌ |
| +cos4‌+cos4‌ |
] =[(sin4‌+cos4‌)+(sin4‌+cos4‌)]+[] Further simplify the above,
x‌‌=[(1−2sin2‌cos2‌)+(1−2sin2‌cos2‌)]+[‌+1+‌] ‌‌=[2−‌4sin2‌cos2‌−‌4sin2‌cos2‌]+[‌+1] ‌‌=3
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