First choose any two input values for c that crest an interval of 3 such as a and s + 3 use these values to complete the proof

Answer 1

Let a = 2 and s = 1.
Then, a + 3 = 2 + 3 = 5 and s + 3 = 1 + 3 = 4.

Since 5 - 4 = 1, the interval formed by a + 3 and s + 3 is 3.

Therefore, if a = 2 and s = 1, then s + 3 and a + 3 form an interval of 3.