Moderate -0.8 This is a straightforward two-part question requiring factorization of a simple quadratic (y-3)(y-4)=0, then substitution y=x² to solve the quartic. The 'hence' structure explicitly guides students through the method, making it easier than average with minimal problem-solving required.
for factors giving two terms correct or attempt at quadratic formula or completing square
\(y = 3\) or \(4\) cao
A1
or B2 (both roots needed)
\(x = \pm\sqrt{3}\) or \(\pm 2\) cao
B2
B1 for 2 roots correct or ft their \(y\) (condone \(\sqrt{3}\) and \(\sqrt{4}\) for B1)
# Question 9:
| $(y-3)(y-4)[=0]$ | M1 | for factors giving two terms correct or attempt at quadratic formula or completing square |
| $y = 3$ or $4$ cao | A1 | or B2 (both roots needed) |
| $x = \pm\sqrt{3}$ or $\pm 2$ cao | B2 | B1 for 2 roots correct or ft their $y$ (condone $\sqrt{3}$ and $\sqrt{4}$ for B1) |
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