Trigonometry Answers

If tana=P/Q,prove that Q cos2a+P cos2a=Q

cos^3a sin3a+sin^3a cos3a=3/4sin4a

Sin cube a+cos cube a/sina+cosa=1-1/2sin2a

Find all the complex roots. Leave your answers in polar form with the argument in degrees.
14) The complex fourth roots of -16

An audio speaker that weighs 50 pounds hangs from the ceiling of a restaurant from two cables(45 degrees left and 35 degrees right). To two decimal places, what is the tension in the two cables?

Find the work done by a force of 2 pounds acting in the direction of 35° to the horizontal in moving an object 8 feet from (0, 0) to (8, 0).

Calculate llF1ll and llF2ll when delta=150 degrees and theta=30 degrees.

Evaluate 1-2cos²25/(1-2sin²65)

Evaluate 1-2cos²25/1-2sin²65

If sin∅=3/5 and ∅ is acute find sin½∅