Farazthesizzler Posts: 1, Reputation: 1 New Member #1 Jan 23, 2018, 01:24 AM
Help with the point of the curve(differentiation)
Question: Find the point on the curve y=x2+1 that is closest to the point (18,1).
Please see the image and that’s where I’m stucked- after taking the first derivate. Please solve it further step by step completely. It’d mean a lot
Attached Images

 ebaines Posts: 12,132, Reputation: 1307 Expert #2 Jan 29, 2018, 07:21 AM
All you need do is find the value for x that makes the numerator of the derivative equal to zero, in other words that satisfies the equation $2x^3 + x -18 = 0$. In general solving a cubic equation can be difficult, but in this case it's pretty easy to guess the correct answer. Give it a try...