prove that : sin48°sec42°+cos48°cosec42°=2
Answers
Answered by
2
Step-by-step explanation:
Given sin48
∘
sec42
∘
+cos48
∘
csc42
∘
we know that,
secθ=
cosθ
1
and cscθ=
sinθ
1
∴
cos42
∘
sin48
∘
+
sin42
∘
cos48
∘
We have,
cos(90−θ)=sinθ, sin(90−θ)=cosθ
∴
cos(90−48)
∘
sin48
∘
+
sin(90−48)
∘
cos48
∘
=
sin48
∘
sin48
∘
+
cos48
∘
cos48
∘
sin48
∘
+
cos48
∘
cos48
∘
=1+1
=2
∴ sin48
∘
sec42
∘
+cos48
∘
csc42
∘
=2
hence proved
Answered by
0
Given sin48
sec42
+cos48
csc42
we know that,
secθ=
cosθ
1
and cscθ=
sinθ
1
∴
cos42
sin48
+
sin42
cos48
We have,
cos(90−θ)=sinθ, sin(90−θ)=cosθ
∴
cos(90−48)
sin48
+
sin(90−48)
cos48
=
sin48
sin48
+
cos48
cos48
=1+1
=2
∴ sin48
sec42
+cos48
csc42
=2
hence proved
sec42
+cos48
csc42
we know that,
secθ=
cosθ
1
and cscθ=
sinθ
1
∴
cos42
sin48
+
sin42
cos48
We have,
cos(90−θ)=sinθ, sin(90−θ)=cosθ
∴
cos(90−48)
sin48
+
sin(90−48)
cos48
=
sin48
sin48
+
cos48
cos48
=1+1
=2
∴ sin48
sec42
+cos48
csc42
=2
hence proved
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