Answer:

Step-by-step explanation:
<u>The Derivative of a Function</u>
The derivative of f, also known as the instantaneous rate of change, or the slope of the tangent line to the graph of f, can be computed by the definition formula

There are tables where the derivative of all known functions are provided for an easy calculation of specific functions.
The derivative of the inverse tangent is given as

Where u is a function of x as provided:

If we set

Then


Taking the derivative of y
![y'=3[tan^{-1}(x+\sqrt{1+x^2})]'](https://tex.z-dn.net/?f=y%27%3D3%5Btan%5E%7B-1%7D%28x%2B%5Csqrt%7B1%2Bx%5E2%7D%29%5D%27)
Using the change of variables
![\displaystyle y'=3[tan^{-1}u]'=3\frac{u'}{1+u^2}](https://tex.z-dn.net/?f=%5Cdisplaystyle%20y%27%3D3%5Btan%5E%7B-1%7Du%5D%27%3D3%5Cfrac%7Bu%27%7D%7B1%2Bu%5E2%7D)

Operating


Her call lasted 48 minutes
Hope this helps :)
I thinks it’s probably 72
I’m not completely sure tho . Pls lmk if I’m wron
Answer:
Let's start first with sin(x+y) :
- sin(x+y)
- sin(x)*cos(y)+cos(x)*sin(y)
Now with sin(x)+sin(y) :
- sin(x)+sin(y)
- 2*sin[(x+y)/2] * cos[(x-y)/2]
We can see that both expressions are far away from being equal