Respuesta :

Answer:0.2588

Step-by-step explanation:

To find the exact value for

Sinpi/12

pi=180°

So

Sin 180/12

Sin15°

=0.2588

Answer:

Step-by-step explanation:

The answer given below is not in the form you need.  You need the form that includes radicals, not decimals.  The formula for the half angle of sin is

[tex]sin(\frac{\theta}{2})=+/-\sqrt{\frac{1-cos\theta}{2} }[/tex] so we need to find out what theta is.  If our problem is

[tex]sin(\frac{\pi}{12})[/tex] , to get that into half angle form, it would be rewritten as

[tex]sin(\frac{\frac{\pi}{6} }{2})[/tex] so

[tex]\theta=\frac{\pi}{6}[/tex]

Look to your unit circle to find the EXACT VALUE of the cos of that angle.  

[tex]cos(\frac{\pi}{6})=\frac{\sqrt{3} }{2}[/tex]

Filling that into the formula for the half angle sin:

[tex]sin(\frac{\frac{\pi}{6} }{2})=+/-\sqrt{\frac{1-\frac{\sqrt{3} }{2} }{2} }[/tex]  Doing a bit of simplifying gives you

[tex]+/-\sqrt{\frac{\frac{2}{2} -\frac{\sqrt{3} }{2} }{2} }[/tex] and

[tex]+/-\sqrt{\frac{\frac{2-\sqrt{3} }{2} }{2} }[/tex]  and

[tex]+/-\sqrt{\frac{2-\sqrt{3} }{2}* \frac{1}{2} }[/tex] gives you

[tex]+/-\sqrt{\frac{2-\sqrt{3} }{4} }[/tex] which finally simplifies to

[tex]+/-\frac{\sqrt{2-\sqrt{3} } }{2}[/tex]

That's the answer in exact format.

Q&A Education