Mathematics 9709 · AS & A Level · Quadratics

Quadratics — practice question

(a)[3]

Determine the values of the constant $m$ for which the line $y = mx$ is tangent to the curve $y = 2x^2 - 4x + 8$.

(b(i))[2]

The function $f$ is defined for $x \in \mathbb{R}$ by $f(x) = x^2 + ax + b$, where $a$ and $b$ are constants. The roots of the equation $f(x) = 0$ are $x = 1$ and $x = 9$. Determine the values of $a$ and $b$.

(b(ii))[2]

Determine the coordinates of the vertex of the curve $y = f(x)$.

Worked solution & mark scheme

This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: Set $y=2x^2-4x+8$ equal to $y=mx$.

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