Attempt following question by selecting a choice to answer. c Find the area of the surface obtained by rotating the curve y = 2x + 1,1 ≤ x ≤ 2 about x-axis.e c A. c85π B. c163π C. c45π D. c165π E. c83π

Step 2: If f ′(x) is continuous on [a, b] and the curve y = f(x) is rotated about x - axis, then the area of the surface of revolution is, A = 2π∫ab |f(x)| 1+(f′(x))2dx

Step 3: f ′(x) = 2 is continuous on [1, 2].

Step 4: Surface area of revolution = ∫12 2πf(x) 1+(f′(x))2dx

Step 5: = 2π∫12 (2x + 1) 1+4dx

Step 6: = 25π∫12 (2x + 1) dx

Step 7: = 25π (x^{2} + x)12

Step 8: = 25π (6 - 2) = 85π

Request for Email

* Please give a valid email id.
* Log into the site atleast once.

Enter your Mail Id:

We have a back-to-school special for all registering before October 15th. You get 1 year free access to iCoachMath.