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) = 0a)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

Answer:Option A - Since cot is an odd function  [tex]2 cot(-\frac{9\pi}{2})[/tex] does not equal  [tex]2 cot(\frac{9\pi}{2})[/tex]               Step-by-step explanation: Given : Sandra wants to evaluate [tex]2 cot(-\frac{9\pi}{2})[/tex]To find : What did she do wrong?Solution : In the first step she took a wrong step because cot is an odd function so [tex]cot(-x)= -cot x[/tex] The exact steps are :[tex]2cot(-\frac{9\pi}{2})=-2cot (\frac{9\pi}{2})[/tex][tex]2cot(-\frac{9\pi}{2})=-2cot (\frac{\pi}{2})[/tex][tex]2cot(-\frac{9\pi}{2})=-2(0)[/tex][tex]2cot(-\frac{9\pi}{2})=0[/tex]Therefore, option A is correct .