draw a rectangled triangle and mark an angle as and mark appropriate lengths of the sides which will give and find the unknown side so that you can find . this is same as using the identity
draw a rectangled triangle and mark an angle as and mark appropriate lengths of the sides which will give and find the unknown side so that you can find . this is same as using the identity
I'm sorry, but I don't understand you wrote....
Thanks for the attempt though :-)
I tried your triangle method and got 2/9, is this correct?
No this isn't correct, but it's close. The identity that BAdhi posted is one of the most useful in Trigonometry, and really should be memorized. Knowing it will make much of the computation you end up doing so much easier.