Question

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

Answer 1

8.6615988

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