Surface Area of revolution about the y-axis of x^2]4 - lnx2

In this video, I showed how to compute the surface area of revolution of a function about the y-axis. i explained how to choose the radius of revolution depending on what axis the revolution is about.

[Samir-zbxk]

I feel like the question should include the fact that the base of the solid is also bounded by the y-axis, since that is how you drew it but it's not obvious that thats the case from only the initial information given; perhaps something like "The base of a solid is given by the region bounded by the y-axis and the graph y = x²/4 - ln(x)/2 on the interval x∈[1, 2]. This region is then rotated about the y-axis to form the solid. Determine the surface area of this solid." Regardless, awesome question and great explanation

[surendrakverma]

Thanks Sir for the excellent explanation.

[RobG]

Wouldn't the shape formed by rotation be more like a curved collar instead of a bowl?

[anisa]

Hi sir one question why ds is square root of 1+f'(x)? is it the same for all the problem?If you have video about it i will make sure to watch ❤

[ThenSaidHeUntoThem]

Lol 😂 We know all the x' s are greater than 1 for this problem. So, positive.

[matheodaniloalvitreslopez]

This question is to be answered until 11:59 am, for those who have the last digit of their DNI 5: What is the letter you like the most among A, B, C, I, N, The m?

[matheodaniloalvitreslopez]

Esta pregunta es para que me respondan hasta las 11:59 am, para los que tienen el último dígito de su DNI 5 : ¿Cuál es la letra que les gusta más entre la A, la B, la C, la I, la N, la M?

[Harrykesh]

professor bring some tough problem these are too easy