$6\mathrm{.}2$ Consider running gradient descent with a fixed learning rate $\backslash$gamma $.$ For each of the following, we plot the function value over $10$ steps $($the function is different each time$).$ Decide whether the learning rate is probably too high, too low, or about right.

$1.$ f$1$: $100,99,98,97,96,95,94,93,92,91$

$2.$ f$2$: $100,50,75,60,65,45,75,110,90,85$

$3.$ f$3$: $100,80,65,50,40,35,31,29,28,27\mathrm{.}5,27\mathrm{.}34.$ f$4$: $100,80,60,40,20,0,20,40,60,80,100$