How do I find the value of sin 150?

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Answer 1 · 2015-09-16T03:13:37

Find sin 150

You may find sin 150 by 2 ways:

First way. Trig Table gives --> sin 150 deg, or $sin (\frac{5 π}{6})$ $sin ((5pi)/6)$ , = 1/2
Second way: by the trig unit circle.

$sin (\frac{5 π}{6}) = sin (\frac{π}{6}) = \frac{1}{2}$ $sin ((5pi)/6) = sin (pi/6) = 1/2$
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Answer 2 · 2018-08-05T05:45:50

$sin (150^{\circ}) = \frac{1}{2}$ $sin(150^@) = 1/2$

$sin (150^{\circ}) = sin (180^{\circ} - 30^{\circ}) = {sin 30}^{\circ}$ $sin(150^@) = sin(180^@-30^@) = sin 30^@$

because $sin$ $sin$ is positive in the 2nd quadrant, so

${sin 30}^{\circ} = \frac{1}{2}$ $sin 30^@ = 1/2$