You can try to show this by induction:
• According to the given closed form, we have , which agrees with the initial value <em>S</em>₁ = 1.
• Assume the closed form is correct for all <em>n</em> up to <em>n</em> = <em>k</em>. In particular, we assume
and
We want to then use this assumption to show the closed form is correct for <em>n</em> = <em>k</em> + 1, or
From the given recurrence, we know
so that
which is what we needed. QED
A coin has two sides, which means it has a 1/2 chance of landing on each individual side when you flip the coin. Since there is a 1/2 chance of landing on each side, you could expect the coin to land on "Heads' 75 times.
The student went wrong in step three. the solutions should have been -3 and 5