We know that the slope of the tangent line at a point on a curve is found by evaluating the derivative of the curve at that point.(adsbygoogle = window.adsbygoogle || []).push({});

Say we have the curve y=2x.

Say I wanted to find the tangent line at x=4

dy/dx=2

The first derivative is a constant, which is not surprising since the curve is always changing at the same rate.

However, since the first derivative is a constant, how can I find the equation of the tangent line at x=4? We can't say it's y=2 since that line does not intersect y=2x at x=4.

Can anyone help me

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# Tangent line of a line

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