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    Can someone pls help me with question 10 (last one) part B! I've been stuck on it for like 2 hours having no clue what to do ..
    I opened solution banks it started from the gradient of the tangent being 1/q... How does it know???
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    (Original post by pondsteps)
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    Can someone pls help me with question 10 (last one) part B! I've been stuck on it for like 2 hours having no clue what to do ..
    I opened solution banks it started from the gradient of the tangent being 1/q... How does it know???
    Using the chain rule,  \displaystyle \frac{d}{dx}(ln(3x)) = \frac{1}{x}
    From this can find the gradient of the normal, thus the equation of the normal and substitute x=q.
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    (Original post by NotNotBatman)
    Using the chain rule,  \displaystyle \frac{d}{dx}(ln(3x)) = \frac{1}{x}
    From this can find the gradient of the normal, thus the equation of the normal and substitute x=q.
    Doesnt ln(3x) differentiate to give 3/3x ?
    Oh never mind, that simplifies to 1/x
    school boy error
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    (Original post by bobwibbles)
    Doesnt ln(3x) differentiate to give 3/3x ?
    Yes, which can be simplified to 1/x
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    Oh I think I got that thank u .. I found a similar question now (also part b) but also didn't known how to solve it 😭
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