Question 155390
Do exponential functions only model phenomena that grow, or can they also model phenomena that decay? Explain what is different in the form of the function in each case. 
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Exponential Form: y = ab^x
If b>1 the function is a growth function
Ex: y = 2*3^x
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If 0 < b < 1 the function is a decay function
Ex y = 2*(1/3)^x
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Cheers,
Stan H.