Question

Convert the recursive form a1=5, an=2an−1
to the explicit form. (1 point)
Responses

an=5(2)n+1

A sub n is equal to 5 times 2 raised to the n plus 1 power

an=3(7)n

A sub n is equal to 3 times 7 to the n th power

an=2(5)n−1

A sub n is equal to 2 times 5 raised to the n minus 1 power

an=5(2)n−1

Answer 1

an = 5(2)^{n-1}

Reason: it's a geometric sequence with a1 = 5 and ratio r = 2, so a_n = a1 * r^{n-1} = 5·2^{n-1}.