Sometimes I find that I want pupils to focus on one small decision. In the case of trig equations I take a unit circle approach, and link to graphs and the simplified ‘CAST’ diagram.
This task gives them the opportunity to focus on this key decision point in these questions quickly in succession, without having to solve lots of equations. They can then practice solving equations with confidence that they know what this step is about.
Mike Ollerton reminded me of the power of LGEs (learner generated examples) this week. The second question opens up a little bit of creativity and taps into the generation effect. If pupils can successfully do Q2 I think it means they’ve ‘got it’.