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:
x = 25 degrees ∠HKL = 102 degrees
Step-by-step explanation:
The whole thing equals 180, since it is a straight angle
The value of HKL is 180 - 78 = 102
So that means 4x + 2 = 102
Subtract 2 from both sides:
4x = 100
Divide both sides by 4:
x = 25
120 - 3/4y=60
lowest common multiple=4y
480y-3=240y
480y-240y=3
240y=3
y=3/240
y=1/80
Answer: y=1/80
Exchange : 63m = 6300 cm; 56m21cm= 5621cm
So the lengths of the ribbon will be left is : 6300 - 5621 = 679cm = 6.79 m
Hope it helps! If it is, Brainliest please!