The cotangent function is defined as the ratio between cosine and sine of a given angle, i.e.
Since you can't have zero at the denominator, the cotangent function is not defined when the sine is zero.
Let's look at your option:
, so the cotangent is defined here
, so the cotangent is not defined here
, so the cotangent is defined here
, so the cotangent is defined here
we know that
1) Lily swims a 
-meter race
2) She swims the first half in 
seconds
3) She swims the second half in 
seconds
so
To find the total time to swim the whole race sum the time in the first half plus the time in second half
therefore
<u>the answer is</u>
It mean something that is even
(Y-Y1)/(X-X1)
(-9-(-29))/(7-15)
20/-8
-2 1/2
The slope is -2 1/2
Population: six sugar maples
Sample: sap
