Posted by **Scott** on Monday, July 11, 2011 at 1:38pm.

simplify (cos4x-cos2x)/(sin4x+sin2x) the answer choices are : cotx, tanx, cotxtanx, or 1

- Math -
**bobpursley**, Monday, July 11, 2011 at 2:27pm
let x be 45 deg

(cos180-cos90)/(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

(cos120-cos60)/(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

## Answer this Question

## Related Questions

- Trigonometry - Simplify the expression using trig identities: 1. (sin4x - cos4x...
- Pre-Calc - How do I solve this? My work has led me to a dead end. tan(45-x) + ...
- Math please help quick - Which of the following are identities? Check all that ...
- MATH - veify that each equation is an identity cos2x+tan2xcos2x=1 sin4x-cos4x/...
- Math (Trig) - Rewrite the following expression in terms of tan3x: (sin2x + sin4x...
- math - Prove the identity: 1-cos2x/sin2x = 1+tanx/1+cotx I simplified the RS to ...
- Math - 1)A piano tuner uses a tuning fork. If middle C has a frequency of 264 ...
- math - sin2x-cotx = -cotxcos2x Using the various trigonometric identities(i.e. ...
- Trig - Simplify: (cosx + cos2x + cos3x + cos4x + cos5x + cos6x) / (sinx + sin2x...
- maths - prove that 1+sin2x-cos2x / sin2x+cos2x = tanx

More Related Questions