OCR MEI C1 2012 January — Question 8 5 marks

Exam BoardOCR MEI
ModuleC1 (Core Mathematics 1)
Year2012
SessionJanuary
Marks5
PaperDownload PDF ↗
TopicCompleting the square and sketching
TypeComplete square then find vertex/turning point
DifficultyModerate -0.8 This is a straightforward completing-the-square question with standard coefficient manipulation, followed by direct reading of the minimum value from the completed square form. It requires only routine algebraic technique with no problem-solving insight, making it easier than average but not trivial due to the non-unit leading coefficient.
Spec1.02e Complete the square: quadratic polynomials and turning points

8 Express \(5 x ^ { 2 } + 15 x + 12\) in the form \(a ( x + b ) ^ { 2 } + c\).
Hence state the minimum value of \(y\) on the curve \(y = 5 x ^ { 2 } + 15 x + 12\).

8 Express $5 x ^ { 2 } + 15 x + 12$ in the form $a ( x + b ) ^ { 2 } + c$.\\
Hence state the minimum value of $y$ on the curve $y = 5 x ^ { 2 } + 15 x + 12$.

\hfill \mbox{\textit{OCR MEI C1 2012 Q8 [5]}}