I would be very grateful if someone could solve this question for me???
Using the identities for sin (A+B) and cos^2(theta)+sin^2(theta)=1
Find sine 65 degrees?
okay we get started by listing what may be of help here:
;
;
;
with the trigonometric identities:
First we assume
;
therefore we have
,
together with the application of the identities introduced above, which results:
(note that y is less than )
The identities also yield that
Therefore we may find the only real value of y (which isn't easy)
Hence
The bad news is that, I haven't yet figured out how to solve the equation without a calulator. So good luck on that, and I'll put my findings here as soon as I'm getting something.
see this "second" post ...
http://www.mathhelpforum.com/math-he...le-153405.html