Just draw the graph and use transformations to determine the answer. Algebraic, whilst it may be possible, its easier to just apply transformations, esp bc its a mc question.
Nah that takes too long, it's only one mark, I would just take random points from the graph, plug in into a calculator and see if it works, if not then skip to the next one
Fair enough. Tbh tho if you can visualise a cos^-1x graph and know how absing a function works, even plotting points wont rlly be that neccessary
Although even then, there is always room for error so ur method probs works best