When i was at school i used to think that any line that touches a curve at only one point is called as the tangent at that point to the curve! But after reading derivative i think this definition of tangent is not correct at all conditions!(adsbygoogle = window.adsbygoogle || []).push({});

For example,

x-axis cannot be called as tangent at origin to the function y=|x| though it touches the curve at origin only!

second example,

tangent at a point on a curve y=sin x may also touch any other point on the same curve(thus there are two points of intersection)

IS this new concept of tangent i have is right OR the definition of tangent at school is right?

please help!

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# Tangent at a point on a curve

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