If 2x2 + y2 = 17 then evaluate the second derivative of y with respect to x when x = 2 and y = 3. Round your answer to 2 decimal places. Use the hyphen symbol, -, for negative values.

Respuesta :

Answer:

y''=-1.26

Step-by-step explanation:

We are given that [tex]2x^2+y^2=17[/tex]

We have evaluate the second order derivative of y w.r.t. x when x=2 and y=3.

Differentiate w.r.t x

Then , we get

[tex]4x+2yy'=0[/tex]

[tex]2x+yy'=0[/tex]

[tex]yy'=-2x[/tex]

[tex]y'=-\frac{2x}{y}[/tex]

Again differentiate w.r.t.x

Then , we get

[tex]2+(y')^2+yy''=0[/tex] [tex](u\cdot v)'=u'v+v'u)[/tex]

[tex]2+(y')^2+yy''=0[/tex]

Using value of y'

[tex]yy''=-2-(-\frac{2x}{y})^2[/tex]

[tex]y''=-\frac{2+(-\frac{2x}{y})^2}{y}[/tex]

Substitute x=2 and y=3

Then, we get [tex]y''=-\frac{2+(\frac{4}{3})^2}{3}[/tex]

[tex]y''=-\frac{18+16}{9\times 3}=-\frac{34}{27}[/tex]

Hence,y''=-1.26