Yes, but not at the level of mathematics you are at.
In elementary statistics, the line of best fit (if it exists) is always a straight line representing a linear relationship between two variables. The equation of the line is most often calculated using the least squares method. [This minimises the sum of the squares of the vertical differences between the values "predicted" by the line and those actually recorded. The process always leads to a straight line.
However, in more advanced statistics, you will learn about transformations. If the relationship between two variables, X and Y, is an inverse relationship, then the relationship between 1/X and Y is linear and you can fit a linear best fit line to the data set given by 1/X and Y. This can then be used to calculate the best fit inverse curve.
Yes but phrased differently
A line of best-fit.
Because the "best fit" line is usually required to be a straight line, but the data points are not all on one straight line. (If they were, then the best-fit line would be a real no-brainer.)
Finding the line of best fit is called linear regression.
A best-fit line is the straight line which most accurately represents a set of data/points. It is defined as the line that is the smallest average distance from the data/points. Refer to the related links for an illustration of a best fit line.
The line of best fit does not have to start from 0.
Yes but phrased differently
The line that minimized the sum of the squares of the diffences of each point from the line is the line of best fit.
A line of best-fit.
Because the "best fit" line is usually required to be a straight line, but the data points are not all on one straight line. (If they were, then the best-fit line would be a real no-brainer.)
What is the difference between a trend line and a line of best fit
The line of best fit is the best possible answer you can get from raw data. They also can be used to make predictions.
The line of best fit does not have to pass through the 0 (origin) and rarely does
Finding the line of best fit is called linear regression.
demand line shows an inverse relationship
A best-fit line is the straight line which most accurately represents a set of data/points. It is defined as the line that is the smallest average distance from the data/points. Refer to the related links for an illustration of a best fit line.
A line does not have an inverse!