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If xy = e^y = e, find the value of y ′′ at the point where x = 0.

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Final answer:

To find y'' at x = 0, first differentiate the given equation twice with respect to x. Then substitute x = 0 into the equation to find the value of y''.

Step-by-step explanation:

To find the value of y'' at the point where x = 0, we need to differentiate the equation xy = e^y = e twice with respect to x. Let's start by differentiating both sides of the equation with respect to x:

1. Differentiating xy = e^y = e:

y + xy' = e^y * y' = 0

2. Differentiating again:

(y' + xy'') + x(y'' + y'^2) = 0

Now, substitute x = 0 into the equation:

y'' = -y'^2/y

Since x = 0 is given, we can substitute it into y = e^y = e:

e = e^y where y = 1

Therefore, when x = 0, y'' = -y'^2/y = -1^2/1 = -1

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