cosine rule

[kindred wraith]

Talking about part b

[light goblet]

it's talking about finding the value of cos(x),
using the fact that sin(x) = opposite / hypoteneuse you can construct a seperate triangle and find cos(x) to be the adjacent / hypoteneuse

but this method isn't really a proper way to find two solutions

you should use the method from the mark scheme

[kindred wraith]

What method did they do in part b? I know the cosine rule has cos but they didn’t include cos. Which is why I’m confused

<@&791435371564892232>

[light goblet]

part b is cosine rule

[kindred wraith]

Yes

[light goblet]

and they did use cos

cos(x) = +-(4/5)

[kindred wraith]

Ohhhh