trig - prove that :tan20 tan30 tan40 =tan10
precalculus - Write each expression as sine, cosine, or tangent of an angle. ...
Pre-Calculus - I need help on these problems they are from my study guide and i ...
Trigonometry - Prove that sin50° - sin70° + sin10° = 0
Trigonometry - Prove that tanx+cotx=2sec(2x) Thank you! :)
Trigonometry - Prove that tan2A = (sec2A+1)√sec˛A-1
Trigonometry - Prove that sec8A-1/sec4A-1 = tan8A/tan2A
Trigonometry - Prove it is an identity. (sin^2x)/(tanx)=sinxcosx
Math trigonometry - Prove sinA/1+cosA =tan1/2A
Trigonometry - If A + B + C = 180° prove that cos2A + cos2B – cos2C = -1 -...