Show that f(x, y) = 5x eˣʸ is differentiable at (1, 0) and find its linearization there. Then use it to approximate f(1.1, −0.1).

Respuesta :

Answer: The approximate f(1.1,-0.1) is 4.92.

Step-by-step explanation:

Since we have given that

[tex]f(x,y)=5xe^{xy}[/tex]

at (1,0),

we get [tex]f(1,0)=5[/tex]

Partial derivative would be

[tex]f_x=5e^{xy}+5xye^{xy}=5e^{xy}(1+xy)[/tex]

So,

[tex]f_x(1,0)=5[/tex]

Similarly,

[tex]f_y=5x^2ye^{xy}[/tex]

So, [tex]f_y(1,0)=5[/tex]

Now,

[tex]L(x,y)=f(1,0)+f_x(1,0)(x-1)+f_y(1,0)(y-0)\\\\L(x,y)=5+5(x-1)+5y\\\\L(x,y)=5+5x-5+5y\\\\L(x,y)=5x+5y[/tex]

L(1.1,-0.1)=[tex]5(1.1)-5(0.1)=5[/tex]

and

f(1.1,-0.1) = [tex]5(1.1)e^{1.1\times -0.1}=4.92[/tex]

Hence, the approximate f(1.1,-0.1) is 4.92.