Question

$\sin(49)$
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Answer 1

Answer:

0.756

Step-by-step explanation:

Let f(x) = sin x

Now f’(x) = cos x

Now f(x+ δx) - f(x) = f’(x).δx

f(x+ δx) - f(x) = cos x . δx

Putting x = 45°, δx = 4° = 4. 0.01745 radian = 0.0698 radian ( since 1° = 0.01745 radian)

f(49°) - f(45°) = cos 45° . 0.0698

sin 49° - sin 45° = cos 45° . 0.0698

sin 49° - 1/√2 = 1/√2 . 0.0698

sin 49° - 0.707 = 0.707 . 0.698

sin 49° = 0.707 + 0.049

sin 49° = 0.756 (approx)

Answer 2

Hey friend,

Here is the solution :-

$\sin(49) = \sin(90 - 41) \\ \\ \sin(90 - 41) = \cos(41)$

I hope this will help you....