Find differentiation of y w.r.t x.
(i) `y=x^(2)-6x` (ii) `y=x^(5)+2e^(x)` (iii) `y=4 ln x +cos x`

Explanation

To find the differentiation of \( y \) with respect to \( x \) for the given functions, we will use the basic differentiation rules. Let's solve each part step by step.

### (i) \( y = x^2 - 6x \)

1. **Identify the function**: We have \( y = x^2 - 6x \).
2. **Differentiate each term**:
- The derivative of \( x^2 \) is \( 2x \) (using the power rule: \( d(x^n)/dx = nx^{n-1} \)).
- The derivative of \( -6x \) is \( -6 \) (the derivative of \( kx \) where \( k \) is a constant is simply \( k \)).
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