Recall from lecture that irrelevant features can cause problems with computation, interpretation and even statistical performance.

The following table shows three features, from left to right, they are f$1(1$st column$),$ f$2(2$nd column$),$ and f$3(3$rd column$),$ for a small dataset with four instances in rows.

Which features are irrelevant, or in other words, can be written as a linear combination of other features? $($For each feature specify if it is irrelevant "yes", or not $"$no$".)$

f$1$ f$2$ f$3$

$-41-4$

$2-0\mathrm{.}51$

$-82-8$

$-123-12$