Verified Answer :

caylus

Hello,

y=2xe^x
y'=2(e^x+xe^x)=2(x+1)e^x
y''=2(e^x+(x+1)e^x)=2(x+2)e^x

x     |-infinite   -2  0    +infinite
e^x | ++++++++++++++++++
x+2 |------------0 +++++++++++
y''    | -----------0 +++++++++++

y''<0 if x<-2
The interval on which the graph is concave down is (-infinite -2[

Using the second derivative, it is found that the graph is concave down on the interval \((-\infty, -2)\).

A function is concave down when the second derivative is negative.

The function is:

\(f(x) = 2xe^x\)

The first derivative is as follows, applying the product rule:

\(f^{\prime}(x) = 2e^x + 2xe^x\)

The second derivative is the derivative of the first derivative, given by:

\(f^{\prime\prime}(x) = 2e^x + 2e^x + 2xe^{x} = 4e^x + 2xe^x = e^x(4 + 2x)\)

The exponential is always positive, so the second derivative is negative if:

\(4 + 2x < 0\)

\(2x < -4\)

\(x < -\frac{4}{2}\)

\(x < -2\)

Hence, the graph is concave down on the interval \((-\infty, -2)\).

A similar problem is given at https://brainly.com/question/13539822