- #1
aks_sky
- 55
- 0
1. The problem statement:
greek letters used here: xi, eta
The Mean Value theorem applied to f(x,y) = sin(x^2 + y^2) implies with a = 0 and b = 0.
sin(x^2 + y^2) = 2 xi cos( xi^2 + eta^2)x + 2 eta cos(xi^2 +eta^2) y
find xi and eta or an accurate approximation to them as a function of x and y.
2. What i have tried doing:
Let f(x,y) and its first order partial derivatives be continuos in an open region R and let (a,b) and (x,y) be points in R such that the straight line joining these points lies entirely within R. Then there exists a point (xi, eta) on that line between the endpoints. So we get
f(x,y) = f (a,b) + f_x (xi, eta) (x-a) + f_y (xi,eta) (y-b)
** I am not sure where to go ahead from here, I would just like an idea as to what i can do to find the answer i don't want anyone to solve it as i would love to solve it but i just want someone to shed some light for me to go in the right direction. THANX for all the help.
greek letters used here: xi, eta
The Mean Value theorem applied to f(x,y) = sin(x^2 + y^2) implies with a = 0 and b = 0.
sin(x^2 + y^2) = 2 xi cos( xi^2 + eta^2)x + 2 eta cos(xi^2 +eta^2) y
find xi and eta or an accurate approximation to them as a function of x and y.
2. What i have tried doing:
Let f(x,y) and its first order partial derivatives be continuos in an open region R and let (a,b) and (x,y) be points in R such that the straight line joining these points lies entirely within R. Then there exists a point (xi, eta) on that line between the endpoints. So we get
f(x,y) = f (a,b) + f_x (xi, eta) (x-a) + f_y (xi,eta) (y-b)
** I am not sure where to go ahead from here, I would just like an idea as to what i can do to find the answer i don't want anyone to solve it as i would love to solve it but i just want someone to shed some light for me to go in the right direction. THANX for all the help.