Moderate -0.8 This is a straightforward trig equation requiring only the double angle substitution (let θ = 2x), finding the principal value with a calculator, identifying the second quadrant solution, then dividing by 2. It's a routine textbook exercise with no conceptual challenges, making it easier than average but not trivial since students must handle the range transformation correctly.
2 Solve the equation \(\sin 2 x = 0.3\) for \(0 ^ { \circ } \leqslant x \leqslant 180 ^ { \circ }\). Give your answer(s) correct to \(\mathbf { 1 }\) decimal place.
If > 2 solutions, award B1B0 or B0B1 or B0B0 to candidate's benefit
\(81.3°\)
B1 (1.1)
If two solutions given scoring B0 B0, allow B1 for awrt either answer
[2 marks]
## Question 2:
$8.7°$ | B1 (1.1a) | If > 2 solutions, award B1B0 or B0B1 or B0B0 to candidate's benefit
$81.3°$ | B1 (1.1) | If two solutions given scoring B0 B0, allow B1 for awrt either answer
[2 marks]
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2 Solve the equation $\sin 2 x = 0.3$ for $0 ^ { \circ } \leqslant x \leqslant 180 ^ { \circ }$. Give your answer(s) correct to $\mathbf { 1 }$ decimal place.
\hfill \mbox{\textit{OCR MEI Paper 3 2021 Q2 [2]}}