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September 18, 2014

September 18, 2014

Posted by **Brianna** on Friday, November 4, 2011 at 12:10pm.

sin( 27pi/4 + 17pi/6)

- trig -
**Reiny**, Friday, November 4, 2011 at 12:27pmsin( 27pi/4 + 17pi/6)

= sin(1215° + 510°) --- sometimes I think better with degrees

= sin(1725°)

= sin(285°) ---- 1725 = 4*360 + 285

= - sin 75°

=- sin(45°+30°)

= - [sin45cos30 + cos45sin30]

= - [ (1/√2)(√3/2) + (1/√2)(1/2)]

= - (√3 + 1)/(2√2)

or after rationalizing ...

= -(√6 + √2)/4

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