2007-03-22 04:01:42 · 4 answers · asked by lana l 1 in Science & Mathematics ➔ Mathematics
put that into a fraction
2007-03-22 04:13:19 · update #1
Note that the difference between 165 degrees and 180 degrees is 15 degrees.
so, you can say that you are actually computing for sin 15
sin 15 can be expressed as sin (30/2) allowing us to use the trig identity:
sin (x/2) = sqrt [(1- cos x)/2]
sqrt [(1 - cos 30)/2]
Recall the 30-60-90 triangle...
sqrt [(1 - (sqrt3)/2 )/2]
so that's your answer. If don't know if you can still simplify this further, though.
2007-03-22 04:36:07 · answer #1 · answered by trauma53 2 · 0⤊ 0⤋
Sine 165 degrees does not exist. For right angled triangles Sine theta is the ratio of opposite / hypotenuse and has to be in the range greater than 0 degrees and less than 90degrees.
2007-03-22 04:45:06 · answer #2 · answered by mad_jim 3 · 0⤊ 0⤋
sin 165° = sin 15°
= sin (45 - 30)°
= sin 45°cos 30 - cos 45° sin 30°
= (1/√2). (√3 / 2) - (1 /√2).(1 / 2)
= (1/(2√2).(√3 - 1)
= (1/4).(√2).(√3 - 1)
2007-03-22 04:47:52 · answer #3 · answered by Como 7 · 1⤊ 0⤋
sin 165= 0.2588190451
2007-03-22 04:08:10 · answer #4 · answered by The exclamation mark 6 · 0⤊ 0⤋