2018_Question1_d

2018_Question1_d

Firstly, f(x-2) = (x-2)^2-5(x-2)+7 = x^2-9x+7. So y'=2x-9, which has a root at \frac92. The corresponding y-coordinate is then \frac{81}{4}-\frac{81}{2}+7 which is negative (it’s roughly 20-40+7), so the answer must be (d).

(You could just actually work out what the y-coordinate is exactly, but it’s always nice to save time and avoid the possibility of making mistakes with calculations!)

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Great hint for people prepearing for the exam!