They give the formula as:
Surface Area = (2 • π • r²) + (2 • π • r • height)
However the 2*PI*r^2 part of the formula is used to calculate the 2 "ends" of a cylinder. Since the problem states that you are NOT to count any of surface area of the "ends" then you only need the (2 • π • r • height) part of the formula.
So, r = 3 inches and height = 8 * 3 inches, the side area equals
2 * PI * r * height
2 * 3.14159 * 3 * 24 =

 452.39 cubic inches which is the lateral area.

6 0

3 years ago

The first three terms in the binomial expansion of (a+b)^n in ascending powers of b, are p,q and r respectively. show that q^2/p

katen-ka-za [31]

First 3 terms are a^2 + n a^(n-)1 b + n(n-1)/2 * a^(n-2) b^2

So q^2 / pr = (n^2 * a^(2n-2) * b^2 ) / (1/2 * a^n * (n(n-1) * a^(n-2) * b^2 )

= n^2 * a^2n-2 * b^2

-----------------------------------

1/2 n(n-1) * a^(2n-2) * b^2

= 2n / n - 1 as required

given p = 4, q=32 and r = 96:-

32^2 / 4*96 = 2n / n-1

2n / n-1 = 8/3

6n = 8n - 8

2n = 8

n = 4 answer

7 0

3 years ago