Q6

Part a requires you to prove that b2 - 4ac has a value exceeding zero.

Part b requires you to input x = 1 and reduce the equation into an “obviously incorrect” equation.

Q7

Once you notice that two sides of the parallelogram are vertical, part (ii) can be done using a much easier method: Base of parallelogram x perpendicular height of parallelogram.

Here you can think of PQ as a “base” of 12 units (since both have the same x-coordinates but both have a difference in y-coordinates of 12, which is a change from -4 to 8).

The “height” of the parallelogram is then the difference in x-coordinates of Q and R (since the x-direction and y-direction are perpendicular to each other), which is 10 (a change from -4 to 6).

So, the area of the parallelogram is 12 x 10 = 120 units2.