Intermediate November 2016 Unit 1 Q11

(a) The table below shows some of the values of \(y = 2x^2 - 5x - 1\) for values of \(x\) from \(-2\) to 4.

Complete the table by finding the value of \(y\) for \(x = -1\) and for \(x = 2\). [2]

\(x\)	\(-2\)	\(-1\)	\(0\)	\(1\)	\(2\)	\(3\)	\(4\)
\(y = 2x^2 - 5x - 1\)	\(17\)		\(-1\)	\(-4\)		\(2\)	\(11\)

(b) On the graph paper below, draw the graph of \(y = 2x^2 - 5x - 1\) for values of \(x\) from \(-2\) to 4. [2]

(c) Draw the line \(y = 5\) on the graph paper.

Write down the values of \(x\) where the line \(y = 5\) cuts the curve \(y = 2x^2 - 5x - 1\).
Give your answers correct to 1 decimal place. [2]

Values of \(x\) are …………… and ……………

(d) Circle the equation below whose solutions are the values you have given in (c). [1]

\(2x^2 - 5x - 1 = 0\)   \(2x^2 - 5x - 6 = 0\)   \(2x^2 - 5x - 5 = 0\)

\(2x^2 - x - 1 = 0\)   \(2x^2 - 5x + 4 = 0\)