(i)[2]
Express $f(x)$ in the form $a + b\cos^2 x$, and state the values of $a$ and $b$.
(ii)[2]
State the greatest and least values attained by $f(x)$.
(iii)[3]
Solve $f(x) + 1 = 0$.
Mathematics 9709 · AS & A Level · Trigonometry
Trigonometry — practice question
The function $f$ is defined by $f(x) = 2\sin^2 x - 3\cos^2 x$ for $0 \le x \le \pi$.
Worked solution & mark scheme
This 7-mark question has a full step-by-step worked solution and mark scheme. One marking point: “Applies the identity $\sin^2 x + \cos^2 x = 1$ to rewrite the expression” …
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