If the function `f(x)=2x^2-k x+5` is increasing on `[1,\ 2]` , then `k` lies in the interval (a) `(-oo,\ 4)` (b) `(4,\ oo)` (c) `(-oo,\ 8)` (d) `(8,\ oo)`

Explanation

To determine the values of \( k \) for which the function \( f(x) = 2x^2 - kx + 5 \) is increasing on the interval \([1, 2]\), we follow these steps:

### Step 1: Find the derivative of the function
The first step is to find the derivative of the function \( f(x) \).
\[ f'(x) = \frac{d}{dx}(2x^2 - kx + 5) = 4x - k \]

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