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Finding second Derivatives In Exercise,find the second derivate.
f(x) = (3 + 2x)e - 3x

User Lenniep
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1 Answer

1 vote

Answer:

the question is incomplete, the complete question is "Finding second Derivatives In Exercise,find the second derivate.


f(x)=(3+2x)e^(-3x)"

answer:
(df(x)^(2))/(dx^(2))=(15+18x)e^(-3x)\\,

Explanation:

To determine the second derivative, we differentiate twice.

for the first differentiation, we use the product rule approach. i.e


f(x)=u(x)v(x)\\(df(x))/(dx)=u(x)(dv(x))/(dx)+ v(x)(du(x))/(dx)\\

from
f(x)=(3+2x)e^(-3x) if w assign

u(x)=(3+2x) and the derivative,
(du(x))/(dx)=2

also
v(x)=e^(-3x) and the derivative
(dv(x))/(dx)=-3e^(-3x).

If we substitute values we arrive at


(df(x))/(dx)=(3+2x)(-3e^(-3x))+2e^(-3x)\\(df(x))/(dx)=(-9-6x)e^(-3x)+2e^(-3x)\\(df(x))/(dx)=(-9-6x+2)e^(-3x)\\(df(x))/(dx)=-(7+6x)e^(-3x)\\,

Now to determine the second derivative we use the product rule again

this time, u(x)=(7+6x) and the derivative,
(du(x))/(dx)=6

also
v(x)=e^(-3x) and the derivative
(dv(x))/(dx)=-3e^(-3x).

If we substitute values we arrive at


(df(x)^(2))/(dx^(2))=-((7+6x)(-3e^(-3x))+6e^(-3x))\\(df(x)^(2))/(dx^(2))=-((-21-18x)e^(-3x)+6e^(-3x))\\(df(x)^(2))/(dx^(2))=-((-21-18x+6)e^(-3x))\\(df(x)^(2))/(dx^(2))=(15+18x)e^(-3x)\\,

User Priomsrb
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