Posted by Scott on .
simplify (cos4xcos2x)/(sin4x+sin2x) the answer choices are : cotx, tanx, cotxtanx, or 1

Math 
bobpursley,
let x be 45 deg
(cos180cos90)/(sin180+sin90)=1/(1)=1
so none of the answers are correct, as ctn(45), tan(45), ctn(45)*tan(45), or 1 are not equal to 1
another angle: let x be 30 deg
(cos120cos60)/(sin120+sin(60)=(.5.5)/(.866+.866)=.577
lets check given answers:
ctn30=1.73
tan30=.577
ctn30*tan30=1
1
none of these are equal to .577