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Trigonometric identities challenge problems

Problem

We have two expressions C and D.
C=tan(40°)csc(40°)csc(50°)sec(60°)D=sin2(15°)+sin2(75°)sin(30°)sin(60°)sin(90°)
Evaluate (6C+3D) without using a calculator.
  • Your answer should be
  • an integer, like 6
  • a simplified proper fraction, like 3/5
  • a simplified improper fraction, like 7/4
  • a mixed number, like 1 3/4
  • an exact decimal, like 0.75
  • a multiple of pi, like 12 pi or 2/3 pi
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