The function is .

Let the tangent point as .

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Apply derivative on each side with respect to .

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Slope of the tangent is derivative of the function at the given point. 

At :

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Point-slope form of line equation: .

Substitute point  and slope in the above equation.

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Above tangent line passes through origin.

Therefore,

Thus , the tangent point is .

Substitute in .

Therefore, tangent line equation is .

Graph:

Tangent point is .

Tangent line equation is .

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