find sin, cosine, and the tangent of the angle 11pi/12
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Originally Posted by jumpman23 find sin, cosine, and the tangent of the angle 11pi/12 $\displaystyle \frac{11\pi}{12}$ is half of $\displaystyle \frac{11\pi}{6}$ ... use your half-angle identities.
Or, as an alternative, note that $\displaystyle \frac{11\pi}{12}=\frac{3\pi}4+\frac\pi6.$
sin(11pi/12) = sin(pi - 11pi/12) = sin(pi/12) = sin( pi/3 - pi/4) = 1/sqrt(2)[ sqrt(3) - 1 ] = [ sqrt(6) - sqrt(2) ]/ 2
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