I was wondering if anyone could help me with a question I was trying to work through today in our A-level math class.(adsbygoogle = window.adsbygoogle || []).push({});

1. The problem statement, all variables and given/known data

a. Sketch the graph of y= ln(3x)

b. The normal to the curve at Point Q, with x coordinate q, passes through the origin. Find the equation of the normal and the value of q

2. Relevant equations

I donâ€™t know which to use

3. The attempt at a solution

Part a was not too difficult and I was able to do that

However I have no idea how to tackle part b. I have only been able to express the gradient of the normal as-q, but cannot solve it. I think [but am not sure] that I can get to the equation

ln3q + q^2 = 0

but I cannot solve this.

I would be very grateful for some help.

Thanks

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# Finding normal to ln curve

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