a)sin(75o) = sin(30o + 45o) = sin(30o)*cos(45o) + sin(45o)*cos(30o) = (1/2)*(2/2 ) + (2/2)∗3/2) = (2/2)∗((1+3)/2)=0.9659
b)tan(5*π/12) = tan(3*π/12 + 2*π/12) = tan(π/4 + π/6) = (tan(π/4) + tan(π/6))/(1-tan(π/4)*tan(π/6)) = (1+3/3)/(1−1∗3/3) = 3.732
c)sin(-π/12) = sin(2π/12 - 3π/12) = sin(2π/12)*cos(3π/12) - sin(3π/12)*cos(2π/12) =
sin(π/6)*cos(π/4) - sin(π/4)*cos(π/6) = (1/2)∗(2/2)−(2/2)∗(3/2)=(2/2)∗(1−3)=−0.5176
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