The approximate value of cos ⁡31^ is (Take 1^ =0.0174 )

Question

Accepted Answer

Correct answer: D. (d) Let y= cos ⁡x ,x=30^ = /6 and x+ x=31^ (y) )_x= 6= cos ⁡ ( 6 )= 32 x=1^ =0.0174radian . Consider the function, y=f (x )= cos ⁡x Differentiating w.r.t. x, dy dx=- sin ⁡x ( dy dx )_x= 6=- sin ⁡ 6=- 12 Let y be the change in y due to the change x in x. ∴ y= dy dx x=(- 12) 0.0174= (-0.5 ) 0.0174 ≈-0.0087 ∴f (31^ )=f(30^ +1^ )=y+ y= 32-0.0087= 1.7322-0.0087=0.8573

$The approximate value of cos 31^{\circ} is (Take 1^{\circ} = 0.0174)$

Solution

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