9709 P12 - Nov 2019 - Q9
711
Functions f and g are defined by
\(f(x) = 2x^2 + 8x + 1\) for \(x \in \mathbb{R}\),
\(g(x) = 2x - k\) for \(x \in \mathbb{R}\),
where \(k\) is a constant.
Find the value of \(k\) for which the line \(y = g(x)\) is a tangent to the curve \(y = f(x)\).
