OCR C3 — Question 3 7 marks

Exam BoardOCR
ModuleC3 (Core Mathematics 3)
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicTangents, normals and gradients
TypeTangent parallel to given line
DifficultyStandard +0.3 This is a straightforward two-part differentiation question requiring chain rule application and solving a cubic equation. While it involves multiple steps (differentiate, find gradient at P, find equation, then solve for Q where gradient matches), each step uses standard techniques with no conceptual challenges beyond typical C3 level.
Spec1.07r Chain rule: dy/dx = dy/du * du/dx and connected rates

3. A curve has the equation \(y = ( 3 x - 5 ) ^ { 3 }\).
  1. Find an equation for the tangent to the curve at the point \(P ( 2,1 )\). The tangent to the curve at the point \(Q\) is parallel to the tangent at \(P\).
  2. Find the coordinates of \(Q\).

3. A curve has the equation $y = ( 3 x - 5 ) ^ { 3 }$.\\
(i) Find an equation for the tangent to the curve at the point $P ( 2,1 )$.

The tangent to the curve at the point $Q$ is parallel to the tangent at $P$.\\
(ii) Find the coordinates of $Q$.\\

\hfill \mbox{\textit{OCR C3  Q3 [7]}}