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
Answer:
Step-by-step explanation:
Tito wants to buy some peanut butter to donate as much as possible.
There some brands are given with their price.
we will calculate the price of per ounce peanut butter of each brand.
A. Nutty : 12 ounces for $2.19
cost per ounce =
= $0.1825 ≈ $0.18 per ounce
B. Grandma's : 18 ounces for $2.79
cost per ounce =
= $0.155 ≈ $0.16 per ounce
C. Bee's : 0.28 ounces for $4.69
cost per ounce =
= $16.75 per ounce
D. Save-A-Lot : 40 ounces for $6.60
cost per ounce =
= $0.165 ≈ $0.17 per ounce
The lowest price is $0.16 per ounce. So he should buy Grandma's peanut butter.
Related angle is 45 degrees, set up a triangle and use exact trig values to solve for x and y, then rationalise the denominators