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The value of the expression (sec20 – 1)(1 - cosec20) is:
(A) 1
(B) O
1
(C)-1
(D)
2
Answers
Answered by
0
Answer:
D
Step-by-step explanation:
Correct option is
D
4
Given expression is
sin20
∘
3
−
cos20
∘
1
=2(
sin20
∘
3
/2
−
cos20
∘
1/2
)
=2(
sin20
∘
sin60
∘
−
cos20
∘
cos60
∘
)
=2(
sin20
∘
cos20
∘
sin60
∘
cos20
∘
−cos60
∘
sin20
∘
)
=2(
sin20
∘
cos20
∘
sin(60
∘
−20
∘
)
)
=2
sin20
∘
cos20
∘
sin40
∘
=2×
sin20
∘
cos20
∘
2sin20
∘
cos20
∘
=4
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