(a)[2]
Find the values of $k$ for which the equation $8x^2 + kx + 2 = 0$ has no real roots.
(b)[3]
Solve the equation $8\cos^2 \theta - 10\cos \theta + 2 = 0$ within the range $0^\circ \leq \theta \leq 180^\circ$.
Mathematics 9709 · AS & A Level · Trigonometry
Trigonometry — practice question
Worked solution & mark scheme
This 5-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Using the discriminant condition $b^2-4ac<0$ and arriving at $k^2-64<0$” …
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