11Elimination by equating coefficients (1/2)

The intersection point is a point that lies on both lines. You can use this to calculate the intersection of the two functions.

The method used for this is called elimination by equating coefficients.

How does elimination by equating work?

As an example, consider two straight lines from the previous slides in the course. Write them down as a system of linear equations:

\displaystyle \mathrm{I}) \; \qquad y = 2x + 1

\displaystyle \mathrm{I}) \; \qquad y = 2x + 1

Since you are looking for a point where the two $y$ -values are equal, the right part of the equation must also have the same value:

\displaystyle \mathrm{I}) \; \qquad y = 2x + 1

\displaystyle \mathrm{I}) \; \qquad y = 2x + 1

Now you can equate the two right sides:

\displaystyle \mathrm{I}) \; \qquad y = 2x + 1

Solve the first equation for $x$ !

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