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An exponential function f ( x ) = a ⋅ b x passes through the points (0, 4000) and (3, 2916). What are the values of a and b ?

a = ___ and b =___

Respuesta :

Answer:

a = 4000, b = 0.9

Step-by-step explanation:

The standard form of an exponential function is

y = a[tex]b^{x}[/tex]

To find a and b substitute the given points into the equation

Using (0, 4000), then

4000 = a[tex]b^{0}[/tex] = 4000 × 1 = 4000

Hence a = 4000, thus

y = 4000[tex]b^{x}[/tex]

Using (3, 2916), then

2916 = 4000[tex]b^{3}[/tex] (divide both sides by 4000 )

0.729 = [tex]b^{3}[/tex] ( take the cube root of both sides ), thus

b = [tex]\sqrt[3]{0.729}[/tex] = 0.9