Maths Probelems (1 Viewer)

[od9895]

HI
Could someone please help me simplifying these questions because I tried but my answer is wrong. I dont think the answer is wrong though. Please show all the working so I could understand and do similar problems.

1. sinAcos(A - B) + cosA sin(A-B)
2. cos(A+B)cos(A-B) + sin(A+B)sin(A-B)
3. sin2AcosA - cos2AsinA

Thank you

 

[nightweaver066]

1. Recognising this:
,

And how the question is in the same form,







2. Recognising that

and how the question is in the same form,







3. Recognising that ,

and how the question is in the same form,

 

[Bored_of_HSC]

2 minutes. Is that a record? (in latex)

 

[nightweaver066]

2 minutes. Is that a record? (in latex)

Just happened to see it haha.