Moderate -0.8 This is a straightforward application of the Pythagorean identity to find cos θ, then dividing to get tan θ. It requires only basic trigonometric identities and simple arithmetic with surds, making it easier than average but not trivial due to the exact value requirement.
M2 for \(\sqrt{15}\) seen; M1 for rt angled triangle with side 1 and hyp 4, or \(\cos^2 \theta = 1 - 1/4 \cdot^2\)
$1/\sqrt{15}$ i.s.w. not $+/-$ | $3$ | M2 for $\sqrt{15}$ seen; M1 for rt angled triangle with side 1 and hyp 4, or $\cos^2 \theta = 1 - 1/4 \cdot^2$ | $3$ |