If `y=(a x-b)/((x-1)(x-4))` has a turning point `P(2,\ -1)` , find the values of `a` and `b` and show that `y` is maximum at `P` .

Explanation

To solve the problem, we need to find the values of \( a \) and \( b \) such that the function

\[ y = \frac{ax - b}{(x-1)(x-4)} \]

has a turning point at \( P(2, -1) \) and show that this point is a maximum.

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