Write an explicit formula for An, the nth term of the sequence 7, 42, 252, ...

Step-by-step explanation:

This is a geometric progression.

Givens

a1 = 7

r = 6

Formula

a_n = a1 * r^(n - 1)

a_n = 7 (6)^(n - 1)

Sample

Try n = 3

a_3 = 7*(6)^(3-1)

a_3 = 7*(6)^2

a_3 = 7 * 36

.a_3 = 252      which is exactly what it should be.

whole numbers.

step-by-step explanation:

we are given the average monthly rainfall (in millimeters) model r(m) for the years 1900-2009 as a function of the month number m.

as we can see m is taken for the number of months for years 1900-2009.

we know that number of months can't be a negative number or decimal number or a fraction.

so, the number of months could be only positive whole numbers.

therefore, whole numbers is more appropriate for the domain of r.