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    Im stuck with this differentiation how do you differentiate

    y=4^x

    Im also having trouble with a decay question (p221 q4 edexcel)

    Ѳ=Ae^-kt

    Where Ѳ is the excess of temperature of the cooling body over its surroundings at time t. For a given liquid, k=1/4, Ѳ is measured in degrees C and t is measured in minutes. The surrounding temp is 20 and at t=0 the temp of the liquid is 60

    a)Find A

    Could somebody help me decipher the question, and maybe write the equation with the known information i know how to do the rest im just not sure what the information ive been given corresponds to!
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    y=4^x=exp(x(log4))

    then use the chain rule and you're done for that bit
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    Im stuck with this differentiation how do you differentiate

    y=4^x

    differential of e^x = e^x
    differential of e^f(x) = e^f(x) times the differntial of f(x)
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    (Original post by sexuali)
    Im stuck with this differentiation how do you differentiate

    y=4^x

    differential of e^x = e^x
    differential of e^f(x) = e^f(x) times the differntial of f(x)
    4 = e^(ln(4))

    So y = e^(ln(4))^x = e^(ln(4)x)
    dy/dx = ln(4)e^(ln(4)x) = 4ln4 e^x
 
 
 
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