<PRE><B>Question 61134</B>
How long will it take a sample of radioactive substance to decay to half of its original amount, if it decays according to the function A(t)=450e^.216t, where t is the time in years? Round your answer to the nearest hundredth year.
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It looks like you are starting with 450 units of something.
Half of it would be 225.
But your equation is an increasing function and you are looking
for decay time.  Check your problem again.
The answer to the problem as you posted would give a negative value
for t.
Cheers,
Stan H.
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