I plugged in 4 for the derivative function but I’m getting the wrong answer?

8.6615988

Step-by-step explanation:

f(x) = 3 sin (x) / ( 1 + cos x)

To find the derivative   bottom * d/ dx top  - top d/dx bottom  all over the bottom squared

d/dx = 3 ( ( 1 + cos x)  cos x - sin x( - sin x))   / ( 1 + cos x) ^2

         = 3 ( cos x + cos ^2 x + sin ^2 x)   / ( 1 + cos x) ^2

         = 3 ( 1 + cos  x) /  ( 1 + cos x) ^2

         = 3 / ( 1 + cos x)

Let x = 4

3  /  ( 1 + cos 4)

Assuming x is in radians

3/.346356

8.6615988

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step-by-step explanation:

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