Easy -1.8 This is a straightforward multiple-choice question requiring only basic knowledge that cos(α) = cos(β) when α = ±β + 360n°. Students substitute θ - 20° = ±60° to get θ = 80° or -40° (equiv. 320°), then select from given options. Single mark, pure recall, no problem-solving.
2 Given that
$$\cos \left( \theta - 20 ^ { \circ } \right) = \cos 60 ^ { \circ }$$
which one of the following is a possible value for \(\theta\) ?
Circle your answer. [0pt]
[1 mark]
\(40 ^ { \circ }\)
\(140 ^ { \circ }\)
\(280 ^ { \circ }\)
\(320 ^ { \circ }\)
2 Given that
$$\cos \left( \theta - 20 ^ { \circ } \right) = \cos 60 ^ { \circ }$$
which one of the following is a possible value for $\theta$ ?\\
Circle your answer.\\[0pt]
[1 mark]\\
$40 ^ { \circ }$\\
$140 ^ { \circ }$\\
$280 ^ { \circ }$\\
$320 ^ { \circ }$
\hfill \mbox{\textit{AQA AS Paper 2 2022 Q2 [1]}}