Tangent of 90 DegreesDate: 5/24/96 at 13:28:26 From: Anonymous Subject: Trignometry Why is the tangent of 90 degrees "no solution"? Date: 5/28/96 at 20:24:37 From: Doctor Pete Subject: Re:Trignometry There are lots of ways to think about why tan(90) is not defined. You can go by the book: tan(x)=sin(x)/cos(x), but since sin(90)=1 and cos(90)=0, and division by 0 is not allowed, tan(90) has no meaning. Or think about it geometrically: say we have a right triangle ABC, with angle ACB=90. Then look at, say, angle BAC. tan(BAC) = BC/AC, but BAC is less than 90 degrees. We can make angle BAC closer and closer to 90 degrees by increasing the length of BC, but as we keep doing this, AC stays the same so the ratio BC/AC gets infinitely large. So tan(90) has no geometric meaning. (Draw a picture, it'll help a lot.) -Doctor Pete, The Math Forum Check out our web site! http://mathforum.org/dr.math/ |
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