Mathematics 9709 · AS & A Level · Differentiation

Differentiation — practice question

The circle in the diagram has equation $(x - 4)^2 + (y + 1)^2 = 40$. Two parallel tangents, both having gradient $1$, meet the circle at $A$ and $B$.
(a)[3]

Determine the equation of line $AB$, and present your answer in the form $y = mx + c$.

(b)[4]

Determine the coordinates of $A$, with both coordinates expressed in surd form.

(c)[2]

Determine the equation of the tangent at $A$, with your answer in the form $y = mx + c$ and $c$ written in surd form.

Worked solution & mark scheme

This 9-mark question has a full step-by-step worked solution and mark scheme. One marking point: Gradient $-1$

  • Full mark scheme, point by point
  • Step-by-step worked solution
  • Write your answer & get it marked instantly by AI