If \sin\beta is the harmonic mean of \sin\alpha and \cos\alpha ,and \sin\theta is the arithmetic mean of \sin\alpha and \cos\alpha , then which of the following is/are correct? 1.\sqrt{2}\sin(\alpha+ {\pi/{4})\sin\beta=sin2\alpha 2.\sqrt{2}\sin\theta =\cos(\alpha- {\pi/{4}) Select the correct answer using the code given below: [NDA II 2018]

Correct Answer is : Both 1 and 2

NDA Math Miscellaneous

Question : 11 of 24

Marks: +1, -0

If sin‌β is the harmonic mean of sinα and cosα ,and sin‌θ is the arithmetic mean of sinα and cosα , then which of the following is/are correct?
1.√2‌sin(α+‌‌

)‌sin‌β=sin2α
2.√2‌sin‌θ=cos(α−‌‌

)
Select the correct answer using the code given below:

[NDA II 2018]

1 only
2 only
Both 1 and 2
Neither 1 nor 2

Validate

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