Hmm, how did you find thatThere have to be only 5 distinct answers. sin(49pi/30) and sin(53pi/30) are included because
and
So it matters not if you list them as
or
but to keep them distinct for example you can't have and in the list because they are the same.
I just think they chose the smallest values of to use in the list.
A simpler example would be to list instead of
for these questions i was taught to always draw the unit circleHmm, how did you find that
and
??
I'm a bit confused. I know its equal but how did you get it?
Any help would be appreciated, thanks
Ohh thanks, that makes sense. It would be great if you could provide the diagram though!for these questions i was taught to always draw the unit circle
so for example this:
and
sin 45pi/30 would be the negative y axis bc its 3pi/2, with 49pi/30 and 41pi/30 equally spaced on each side. Sin is negative in 3rd and quadrant, and both these angles represent the same length bc its equally spaced from sin45pi/30, so they would give the same values, so u cancel one out.
Also for exams i was told to always use the smaller angle if it repeats so u would take 41pi/30. lmk if u need a diagram
Thanks! Method 3 looks useful3 ways.
1. Check with calculator
and
2. Use sum to product
and
3. Use symmetry
and