Can you help me here please?

Question

anonymous · Answer

attachment

callisto · Answer

For (a), what do you think?

anonymous · Answer

Ok

callisto · Answer

Nah?

anonymous · Answer

nah? What do you mean?

callisto · Answer

Hmm... nothing, sorry, what do you think for (a)?

anonymous · Answer

For this, Should I find the reference angle?

callisto · Answer

Hmm, for these kind of question, you need to consider angle in each quadrant. I mean which quadrant(s) give(s) you a negative value for sine ratio

anonymous · Answer

Quadrant 3 and 4

callisto · Answer

So, how many possible value for theta?

anonymous · Answer

2 right?

callisto · Answer

yes :)

callisto · Answer

and you've also got the answer for (b), do you know why?

anonymous · Answer

because the solutions lie in q3 and q4

anonymous · Answer

How do I explain answer a though? Like I get why it would be 2solutions but is there a better explanation?

anonymous · Answer

@DhananjayMaurya, Thank you for the medal:)

callisto · Answer

because there are 2 quadrants give negative values for sine ratio, so there are 2 solutions :P Not sure if this is correct

anonymous · Answer

Ok, that kind of makes sense:). 
For question 3,is the reference angle by any chance -0.4468?

callisto · Answer

if -1≦sin theta ≦1 , then it is possible

anonymous · Answer

What formula would I normally use to find the reference angle? I forget

callisto · Answer

sin theta = sth
theta = sin^-1 sth

anonymous · Answer

yeah. Thats what i put. Sin-1 (-0.4321)
So reference angle -0.4468 is correct right>?

callisto · Answer

nope.. sin^-1 is arc sin

anonymous · Answer

Ok, so my reference angle is 25.60 degrees right?

callisto · Answer

25.60 is in quadrant I, you need the angle in quadrant III and IV~

anonymous · Answer

I would make it -25 but isnt reference angle always the absolute value?

callisto · Answer

-25.60 = 360-25.60 = angle in quadrant IV :)

anonymous · Answer

so reference angle is not +25 but -25?

callisto · Answer

One of the reference angle is 360-25.60

anonymous · Answer

And the two possible solutions are 

theta1 = 180 + 25.6 = 205.6 degrees 
theta2 = 360-25.6 = 334.4 degrees

anonymous · Answer

right?

callisto · Answer

Yup~~~

anonymous · Answer

Thank you. Sorry to bother you, Im sure youre busy. Thank you:)

callisto · Answer

I'm sorry.... really sorry that I didn't respond right after you had!!!