Find the formula for an exponential function that passes through the two points given. (x, y) = −1, 9 2 and (x, y) = (3, 72)

Question

Find the formula for an exponential function that passes through the two points given.

(1,(9/2)) and (3,72)

Answer 1

y = k*B^x

9/2 = k*B^1 = k*B

72 = k*B^3

72 = (9/2)*B^2

16 = B^2

B = 4 <--- only positive base allowed

then k = 72/64 = 9/8

y = (9/8)(4^x)