You are here:
- Home
- Science
- Math for Kids
- Geometry
- Trig Identities
Geometry/Trig Identities
Advertisement
Question
I am to verify 1-(sinx- cosx)^2/ sin x= 2cos x
I got as far as cos^2x+ cos^2x/ sinx; which may or may not be incorrect. Please help
Hi Denaye!
You need to verify this identity: [1-(sin x-cos x)^2]/sin x=2cos x. Note the brackets. Be sure to always put them in exactly.
[1-(sin x-cos x)^2]/sin x
Expand the square.
[1-(sin²x-2sinxcosx+cos²x)]/sin x
Bring the sin²x+cos²x together, using the identity sin²x+cos²x=1.
[1-(1-2sinxcosx)]/sin x
Add along the numerator.
2sinxcosx/sin x
Cancel the sin x.
2cos x.
Thanks for asking,
Azeem
Related Articles
Azeem Hussain
Expertise
I can answer mostly any kind of question dealing with of Math 536 and below, my forte being in parabolic functions and analytical geometry.
Experience
Drop-in tutor at Champlain College since 2010.
I am neither a professor nor a teacher of this subject. I am merely a student who is good at mathematics and enjoys being of service to his community. I frequently tutor people in math and the results are usually great.
Education/Credentials
Presently enrolled in Materials Engineering at McGill University.
Diploma of Collegiate Studies; Pure and Applied Science, Champlain College Saint-Lambert.
Diploma of Secondary Studies from Chambly Academy High School.
Being a Quebecer, I am fluent in English and French and can respond to questions easily in both languages.
©2012 About.com, a part of The New York Times Company. All rights reserved.