Answer:
60°C
Step-by-step explanation:
This is a great example of a problem that looks really complicated, but can be broken down and easily understood!
First, we want to know the temperature the instant it is removed from the heat source. In that case, the time that has elapsed after it has been removed is 0, so we're looking for:
[tex]T(0)=55e^{-0.1(0))}+15=55e^{0}+15[/tex]
Now, any number raised to to the power of zero is 1, so this becomes:
[tex]T(0)=55(1)+15=60[/tex]
For more information on why any number raised to the zero power is 1, I highly recommend researching if it interests you. One of the most intuitive ways is to think of the pattern of exponents:
[tex]3^{3}=3*3*3=27[/tex]
[tex]3^{2}=3*3=9[/tex]
[tex]3^{1}=3[/tex]
You might notice that with each decrease in power, it can be read as dividing the expression by three, so following that pattern gives:
[tex]3^{0}=\frac{3}{3}=1[/tex]
And if we follow the division pattern, we do end up going into negative exponents correctly:
[tex]3^{-1}=\frac{1}{3^{1}}[/tex]
[tex]3^{-2}=\frac{1}{3^{2}}=\frac{1}{9}[/tex]
[tex]3^{-3}=\frac{1}{3^3}=\frac{1}{27}[/tex]
