Find the values of `' a '` for which the function `f(x)=sinx-a x+4` is increasing function on `R` .

Explanation

To find the values of \( a \) for which the function \( f(x) = \sin x - ax + 4 \) is an increasing function on \( \mathbb{R} \), we will follow these steps:

### Step 1: Write down the function
The given function is:
\[ f(x) = \sin x - ax + 4 \]

...