Calculus
posted by Sara on .
Please help me with the following 2 questions.
1. Find the area of the curved surface of a rightcircular cone of radius 6 and height 4 by rotating the straight line segment from (0,0) to (6,4) about the yaxis.
2. Use the Maclaurin polynomial of degree 4 to approximate sin(0.2). The formula given is the sum between k = 0 and infinity of [1^k]/(2k+1)!x^(2k+1). I tried using the following but got it wrong
0.2  (0.2)^3/3! + (0.2)^5/5!  (0.2)^7/7! + (0.2)^9/9!.
Please help.
Thanks

The area of a cone of radius r and slant height s is πrs
r = 6
s^2 = 6^2 + 4^2
s = √52 = 2√13
area = 12π√13
For MacLaurin polynomials, I may be wrong, but I thought you wanted degree 4. That would just be
0 + 1/1! x + 0/2! x^2 + 1/3! x^3 + 0/4! x^4
= x  x^3/3!
= .2  .008/6 = 0.1987 
Thanks Steve.