Mathematics 9709 · AS & A Level · Coordinate geometry

Coordinate geometry — practice question

The coordinates of points $A$ and $B$ are $(3a, -a)$ and $(-a, 2a)$ respectively, and $a$ is a positive constant.
(a(i))[2]

Find the equation of the line through the origin which is parallel to $AB$.

(a(ii))[3]

The length of the line $AB$ is $3\frac{1}{3}$ units. Find the value of $a$.

(i)[2]

Find the equation of the line through the origin which is parallel to $AB$.

(ii)[3]

The length of the line $AB$ is $3\frac{1}{3}$ units. Find the value of $a$.

Worked solution & mark scheme

This 10-mark question has a full step-by-step worked solution and mark scheme. One marking point: The gradient of $AB$ is $-\frac{3}{4}$

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