If sin a =1/4 and cos ß= 1/4, then a + ß
Answers
Step-by-step explanation:


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Class 11
>>Maths
>>Trigonometric Functions
>>Trigonometric Functions of Sum and Difference of Two angles
>>sinalpha + sinbeta = 1/4 and cosalpha +
Question

sinα+sinβ=41 and cosα+cosβ=31
The value of tan(α+β) is
A
725
B
1225
C
1325
D
724
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Solution

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Correct option is D)
sinα+sinβ=3 (i)
$$\Rightarrow 2 \sin\left (\frac{\alpha + \beta} {2}
\right ) \cos\left (\frac{\alpha - \beta} {2} \right ) =
3$$ (ii)
cosα+cosβ=4 (iii)
$$\Rightarrow 2 \cos\left (\frac{\alpha + \beta} {2}
\right ) \cos\left (\frac{\alpha - \beta} {2} \right ) =
4$$ (iv)
Dividing Eq. (ii) by Eq. (i), we have
$$\tan\left ( \frac{\alpha + \beta} {2} \right ) = \frac{3}
{4}$$
⇒sin(α+β)=1+tan2(2α+β)2tan(2α+β)=1+(43)2
Answer:
a + B = 90
Step-by-step explanation:
Sin A = 1/4 = Cos B = Sin (90-B)
therefore A = 90 - B
therefore A + B = 90