Welcome :: Homework Help and Answers :: Mathskey.com
Welcome to Mathskey.com Question & Answers Community. Ask any math/science homework question and receive answers from other members of the community.

13,459 questions

17,854 answers

1,446 comments

807,755 users

Could U pleaseeeeeeeeee prove this?

0 votes
Sin^2x.cos^2x.tan^2x+(cos^2x.cot^2x)/(1+cot^2x)=1-2sin^2x.cos^2x
asked Mar 26, 2013 in TRIGONOMETRY by M Gravity Rookie

1 Answer

0 votes

Sin^2x.cos^2x.tan^2x+(cos^2x.cot^2x)/(1+cot^2x)

Recall the quotient trignometric identity

cotx=cosx/sinx

=Sin^2x.cos^2x.tan^2x+(cos^2x.cos^2x/sin^2x)/(1+(cos^2x/sin^2x))

=Sin^2x.cos^2x.tan^2x+(cos^2x.cos^2x/sin^2x)/((sin^2x+cos^2x)/sin^2x)

Recall pythagoras theorem of trignometry

sin^2x+cos^2x=1

=Sin^2x.cos^2x.tan^2x+(cos^2x.cos^2x/sin^2x)/(1/sin^2x)

Simplify

=Sin^2x.cos^2x.tan^2x+(cos^2x.cos^2x)

Recall the quotient trignometric identity

tanx=sinx/cosx

=Sin^2x.cos^2x.sin^2x/cos^2x.+(cos^2x.cos^2x)

=Sin^2xsin^2x+(cos^2x.cos^2x)

=(sin^2x)^2+(cos^2x)^2

Recall the formulae a^2+b^2=(a+b)^2-2ab

=(sin^2x+cos^2x)^2-2sin^2xcos^2x

Recall pythagoras theorem of trignometry

sin^2x+cos^2x=1

=1-2sin^2xcos^2x

 

answered Mar 27, 2013 by bradely Mentor
.........

Related questions

asked Oct 27, 2019 in TRIGONOMETRY by anonymous
asked Jan 22, 2015 in TRIGONOMETRY by anonymous
asked Nov 20, 2014 in TRIGONOMETRY by anonymous
asked Nov 13, 2014 in TRIGONOMETRY by anonymous
...