The graph of an exponential function passes through (2,−32) and (3,−64). Find the exponential function that describes the graph.

Respuesta :

Answer: [tex]y=(-8)2^x[/tex]

Step-by-step explanation:

The exponential function will have this form:

[tex]y=ab^x[/tex]

We know that the function passes through the points [tex](2,-32)[/tex] and [tex](3,-64)[/tex]. Then, we can substitute the coordinates of the point [tex](2,-32)[/tex]  into [tex]y=ab^x[/tex] and solve for "a":

[tex]-32=ab^2\\\\a=\frac{-32}{b^2}[/tex]

Then, we know that:

[tex]y=(\frac{-32}{b^2})b^x[/tex]

Now, we neeed to substitute the coordinates of the second point [tex](3,-64)[/tex] into [tex]y=(\frac{-32}{b^2})b^x[/tex] and solve for "b":

[tex]-64=(\frac{-32}{b^2})b^3\\\\-64=-32b\\\\\frac{-64}{-32}=b\\\\b=2[/tex]

Substituting the value of "b" into [tex]a=\frac{-32}{b^2}[/tex] we can find "a":

[tex]a\frac{-32}{2^2}\\\\a=-8[/tex]

Therefore, we get that the exponential function that describes the graph, is:

[tex]y=(-8)2^x[/tex]

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