三角比和三魚的應用...
tan2次x -sin2次x 全等 tan2次xsin2次x
幫下我
好難-.-
數學超難題!!!!
2007-03-20 2:14 am
回答 (4)
2007-03-20 2:20 am
✔ 最佳答案
tan^2(x) - sin^2(x)=sin^2(x)(1/cos^2(x) - 1)
=sin^2(x)(1/cos^2(x) - cos^2(x)/cos^2(x))
=tan^2(x)(1 - cos^2(x))
=tan^2(x)sin^2(x)
2007-03-20 08:33:06 補充：
樓下bowie咁攪笑o既
2007-03-27 2:24 am
ok
2007-03-21 3:28 pm
因sinx=cosxtanx,sin^2x=cos^2xtan^2x,1-cos^2x=sin^2x
L.H.S.
=tan^2x-cos^2xtan^2x
=tan^2x(1-cos^2x)
=tan^2xsin^2x
=R.H.S.
L.H.S.
=tan^2x-cos^2xtan^2x
=tan^2x(1-cos^2x)
=tan^2xsin^2x
=R.H.S.
2007-03-20 2:35 am
http://www.ccym.edu.hk/maths/tool/display/Trigonometri%20Ratio.ppt
希望這個ppt幫到你
2007-03-19 18:35:44 補充：
i think the answer is...tan^2(x) - sin^2(x)=sin^2(x)(1/cos^2(x) - 1)=sin^2(x)(1/cos^2(x) - cos^2(x)/cos^2(x))=tan^2(x)(1 - cos^2(x))=tan^2(x)sin^2(x)
希望這個ppt幫到你
2007-03-19 18:35:44 補充：
i think the answer is...tan^2(x) - sin^2(x)=sin^2(x)(1/cos^2(x) - 1)=sin^2(x)(1/cos^2(x) - cos^2(x)/cos^2(x))=tan^2(x)(1 - cos^2(x))=tan^2(x)sin^2(x)
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https://hk.answers.yahoo.com/question/index?qid=20070319000051KK02790