Thanks a lot for the help.

Well it's a tangent to the original equation, so I think that it's definitely correct.

Ah, I get it now. Thank you. So the equation for part b) is y-7x+29=0?

I turned x into x^{-1 }which differentiates to -x^{-2 }which I then multiplied by the numerators (2x and -5). Is that wrong?

I thought the derivative of x^{2}-5x-24 would be 2x-5 (the 24 is zero)?

Thank you so much! It was finding the equation of AB that got me confused on this question. Much appreciated.