OCR C1 2010 January — Question 6 7 marks

Exam BoardOCR
ModuleC1 (Core Mathematics 1)
Year2010
SessionJanuary
Marks7
PaperDownload PDF ↗
Mark schemeDownload PDF ↗
TopicTangents, normals and gradients
TypeFind derivative of simple polynomial (integer powers)
DifficultyEasy -1.3 This is a straightforward C1 differentiation question requiring only basic polynomial differentiation (dy/dx = 2x), substitution to find gradient at a point, using gradient formula between two points, and simple reasoning about intermediate gradients. All parts are routine applications of standard techniques with no problem-solving insight required.
Spec1.07a Derivative as gradient: of tangent to curve1.07i Differentiate x^n: for rational n and sums

6 \includegraphics[max width=\textwidth, alt={}, center]{918d83c3-1608-4482-9d3d-8af05e65f353-2_394_846_1868_648} The diagram shows part of the curve \(y = x ^ { 2 } + 5\). The point \(A\) has coordinates ( 1,6 ). The point \(B\) has coordinates ( \(a , a ^ { 2 } + 5\) ), where \(a\) is a constant greater than 1 . The point \(C\) is on the curve between \(A\) and \(B\).
  1. Find by differentiation the value of the gradient of the curve at the point \(A\).
  2. The line segment joining the points \(A\) and \(B\) has gradient 2.3. Find the value of \(a\).
  3. State a possible value for the gradient of the line segment joining the points \(A\) and \(C\).

6\\
\includegraphics[max width=\textwidth, alt={}, center]{918d83c3-1608-4482-9d3d-8af05e65f353-2_394_846_1868_648}

The diagram shows part of the curve $y = x ^ { 2 } + 5$. The point $A$ has coordinates ( 1,6 ). The point $B$ has coordinates ( $a , a ^ { 2 } + 5$ ), where $a$ is a constant greater than 1 . The point $C$ is on the curve between $A$ and $B$.\\
(i) Find by differentiation the value of the gradient of the curve at the point $A$.\\
(ii) The line segment joining the points $A$ and $B$ has gradient 2.3. Find the value of $a$.\\
(iii) State a possible value for the gradient of the line segment joining the points $A$ and $C$.

\hfill \mbox{\textit{OCR C1 2010 Q6 [7]}}