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Find the exponential function passing through points (-1,4/3) and (3,108)

User RaamEE
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2 Answers

7 votes

Answer:

its 152 i know cause i just did this....

Step-by-step explanation:

User Suneelsarraf
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5.6k points
3 votes

Answer:

An exponential function is in the general form
\mathrm{y}=\mathrm{a}(\mathrm{b})^{\mathrm{x}}

Step-by-step explanation:

(x,y) = (-1,4/3) and (x,y)= (3,108) are the given functions

Therefore,


(4)/(3)=a(b)^(-1)=(a)/(b)


(4)/(3)=(a)/(b) - eq(1)


108=a(b)^(3)=a b^(3)=108-e q(2)

Multiply both sides of the first equation by b to find that


(4)/(3) b=a

Substituting in eq-2 we get


(4)/(3) b^(4)=108


b^(4)=81


\mathrm{b}=\pm 3


\mathrm{b}=+3, \text { then } 108=\mathrm{a}(3)^(3)

which gives a = 4,

henceforth the equation becomes as
\mathrm{y}=4(3)^{\mathrm{x}}


\mathrm{b}=-3 \text { then } 108=\mathrm{a}(-3)^(3)

which gives a = -4,

henceforth the equation becomes as y =
-4(-3)^(x)

However! In an exponential function, b>0, otherwise many issues arise when trying to graph the function.

The only valid function is
4(3)^(x)

User Karthik Manchala
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4.6k points