How to find equation of tangent

[mimie]

How to do this question? Can someone help me, thanks.

 

[MarkFL]

A line passing through the origin can be given by:

[MATH]y=mx[/MATH]
Let the point \(P\) be [MATH](x_1,y_1)[/MATH]. And so we must have:

[MATH]m=\frac{y_1}{x_1}=\left.\frac{d}{dx}\left(\ln(3x)\right)\right|_{x=x_1}[/MATH]
Can you proceed?

 

[Steven G]

Find the slope of the tangent line at point P. Now armed with the slope of the line and a point on the line find the equation of the line.

You need to remember what information you obtain when you find f'(a) for a function f(x).