Find the value of sin2 33+sin2 57
Answers
Answered by
74
Answer :
1
Explanation:
___________________
We know that ,
i )sin(90-A) = cosA
ii) sin²A + cos²A = 1
___________________
Here,
sin² 33° + sin²57°
= sin² 33° + sin²( 90-33 )
= sin² 33° + cos² 33°
= 1
••••
Answered by
12
Answer:
Step-by-step explanation:
Explanation:
We use formulas (A) -
cos
A
=
sin
(
90
∘
−
A
)
,
(B) -
cos
2
A
−
sin
2
A
=
cos
2
A
(C) -
2
sin
A
cos
A
=
sin
2
A
,
(D) -
sin
A
+
sin
B
=
2
sin
(
A
+
B
2
)
cos
(
A
−
B
2
)
and
(E) -
sin
A
−
sin
B
=
2
cos
(
A
+
B
2
)
sin
(
A
−
B
2
)
cos
2
33
∘
−
cos
2
57
∘
sin
2
10.5
∘
−
sin
2
34.5
∘
=
cos
2
33
∘
−
sin
2
(
90
∘
−
57
∘
)
(
sin
10.5
∘
+
sin
34.5
∘
)
(
sin
10.5
∘
−
sin
34.5
∘
)
- used A
=
cos
2
33
∘
−
sin
2
33
∘
−
(
2
sin
22.5
∘
cos
12
∘
)
(
2
cos
22.5
∘
sin
12
∘
)
- used D & E
=
cos
66
∘
−
(
2
sin
22.5
∘
cos
22.5
∘
×
2
sin
12
∘
cos
12
∘
)
- used B
=
−
sin
(
90
∘
−
66
∘
)
sin
45
∘
sin
24
∘
- used A & C
=
−
sin
24
∘
1
√
2
sin
24
∘
=
−
√
2
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