Answer: Hello mate!
in a linear function y = ax + b, the slope is the number a, and the x-axis intercept is the number b.
Here we have the function y = 41, which is a constant function, and in the graph, you can see that this graph is parallel to the x-axis, you can see that this function has a slope equal to 0.
If you want a perpendicular line, you need a constant in the x-axis, this can be something like x = 10, wich is graphed with a line parallel to the y-axis, and you can see that this is perpendicular to y = 41. Then the slope of this function is infinity and its undefined. (this function does not exist)
For the parallel line, every other y = constant is a parallel to our function y = 41, for example, we can take y = 12.
Now, the slope of this function is 0.
A rule in linear equations is: two linear equations are parallel if they have the same slope and a different x-axis intercept; you can see that every y = constant function has a slope of 0, and then all of them are parallel.
For a perpendicular line, if your function is of the form y = ax + b, a perpendicular line is of the form y' = (-1/a)x + c, where c can be any constant.
Again, because in our problem a is equal to 0, here we have a division by 0, and this is why this line is undefined.