Can someone please proofread my work - Conics (1 Viewer)

the-derivative · Jun 7, 2009

Hello guys,

I was wondering if someone could proof read my work for me. The answer is b^2, however I keep on getting a -b^2, and I cannot see where I've made my error. The question states: <meta http-equiv="Content-Type" content="text/html; charset=utf-8"><meta name="ProgId" content="Word.Document"><meta name="Generator" content="Microsoft Word 12"><meta name="Originator" content="Microsoft Word 12"><link rel="File-List" href="file:///C:%5CUsers%5CNATHAN%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_filelist.xml"><link rel="themeData" href="file:///C:%5CUsers%5CNATHAN%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_themedata.thmx"><link rel="colorSchemeMapping" href="file:///C:%5CUsers%5CNATHAN%7E1%5CAppData%5CLocal%5CTemp%5Cmsohtmlclip1%5C01%5Cclip_colorschememapping.xml"><!--[if gte mso 9]><xml> <w:WordDocument> <w:View>Normal</w:View> <w:Zoom>0</w:Zoom> <w:TrackMoves/> <w:TrackFormatting/> <w

unctuationKerning/> <w:ValidateAgainstSchemas/> <w:SaveIfXMLInvalid>false</w:SaveIfXMLInvalid> <w:IgnoreMixedContent>false</w:IgnoreMixedContent> <w:AlwaysShowPlaceholderText>false</w:AlwaysShowPlaceholderText> <w

oNotPromoteQF/> <w:LidThemeOther>EN-AU</w:LidThemeOther> <w:LidThemeAsian>X-NONE</w:LidThemeAsian> <w:LidThemeComplexScript>X-NONE</w:LidThemeComplexScript> <w:Compatibility> <w:BreakWrappedTables/> <w:SnapToGridInCell/> <w:WrapTextWithPunct/> <w:UseAsianBreakRules/> <w

ontGrowAutofit/> <w:SplitPgBreakAndParaMark/> <w

ontVertAlignCellWithSp/> <w

ontBreakConstrainedForcedTables/> <w

ontVertAlignInTxbx/> <w:Word11KerningPairs/> <w:CachedColBalance/> </w:Compatibility> <w:BrowserLevel>MicrosoftInternetExplorer4</w:BrowserLevel> <m:mathPr> <m:mathFont m:val="Cambria Math"/> <m:brkBin m:val="before"/> <m:brkBinSub m:val="--"/> <m:smallFrac m:val="off"/> <m:dispDef/> <m:lMargin m:val="0"/> <m:rMargin m:val="0"/> <m:defJc m:val="centerGroup"/> <m:wrapIndent m:val="1440"/> <m:intLim m:val="subSup"/> <m:naryLim m:val="undOvr"/> </m:mathPr></w:WordDocument> </xml><![endif]--><style>  </style>P (acosθ, bsinθ) lies on the ellipse x^2/a^2 + y^2/b^2 = 1. The tangent at P has two feet perpendicular from the foci S and S’ – respectively T and T’ to this tangent. Prove that ST.ST’ = b^2.

http://img.photobucket.com/albums/v230/Smashedge/Cambridge_1.jpg

Thanks guys!

azureus88 · Jun 7, 2009

You should have used absolute values for ST and ST' as they are both distances (ie. >0).

gurmies · Jun 7, 2009

nice writing xD

the-derivative · Jun 7, 2009

azureus88 said:
You should have used absolute values for ST and ST' as they are both distances (ie. >0).

Wow, I never thought of that.
OMG, that's such a simple solution to it! Thanks.

gurmies said:
nice writing xD

Haha, thanks. =)

Can someone please proofread my work - Conics (1 Viewer)

the-derivative

BCom/LLB (UNSW)

azureus88

Member

gurmies

Drover

the-derivative

BCom/LLB (UNSW)

Users Who Are Viewing This Thread (Users: 0, Guests: 1)