Math, asked by ritabhowmick1989, 1 month ago

If 2sin2β – cos2β = 2, then β is (a) 0ᵒ (b) 90ᵒ (c) 45ᵒ (d) 30ᵒ​

Answers

Answered by sumanojha658
12

Correct answer is: (b) 90ᵒ

2sin2β – cos2β = 2

Then 2 sin2β – (1- sin2β) = 2

3 sin2β =3 or sin2β =1

β is 90ᵒ

Answered by RvChaudharY50
3

Solution :-

→ 2sin²β – cos²β = 2

using cos²A = 1 - sin²A

→ 2sin²β - (1 - sin²β) = 2

→ 2sin²β + sin²β - 1 = 2

→ 3sin²β = 2 + 1

→ 3sin²β = 3

→ sin²β = 1

→ sinβ = ± 1

→ β = 90° , 180° .

Hence, Option (b) 90° is correct answer .

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