Sandra wants to evaluate 2 cot(-9pi/2). her work is shown below. what did she do wrong? 2 cot (-9pi/2) = 2 cot (9pi/2) 2 cot (-9pi/2) = 2 cot (pi/2) 2 cot (-9pi/2) = 2(0) 2 cot (-9pi/2) = 0 a)since cot is an odd function 2 cot (-9pi/2) does not equal 2 cot(9pi/2) b) since cot has a period of (pi) 2 cot(9pi/2) does not equal 2 cot (pi/2) c) since cot evaluated at pi/2 is not 0, 2 cot(pi/2) does not equal 2(0) d) since cot cannot be multiplied by a factor 2(0) does not equal 0

Option A - Since cot is an odd function   does not equal                 

Step-by-step explanation:

Given : Sandra wants to evaluate

To find : What did she do wrong?

Solution : In the first step she took a wrong step because cot is an odd function so

The exact steps are :

Therefore, option A is correct .

(n^3 - n)

= n(n-1)(n+1)

since it is divisible by 3 and 2 ,because it is a multiple 3 consecutive number

if, n-1 is odd then n+1 is also odd, then it is a multiple of 9

but if, n-1 is even then n+1 is also even, then it is a multiple of 4

so, largest multiple = max(9*2, 4*3) = max(18, 12) = 18

mean, 40.6

step-by-step explanation: