Good Afternoon.

I just want to be sure about this question

Using proper set notation, describe the domain of
f(x,y)=cos[1/(y^2-x^2)^1/2]

D= {(xy)|yx}

Am I to shade the positive side of the graph y=x

Thank you.

Question

Good Afternoon.

I just want to be sure about this question 

Using proper set notation, describe the domain of
f(x,y)=cos[1/(y^2-x^2)^1/2]

D= {(xy)|y>x} 

Am I to shade the positive side of the graph y=x  

Thank you.

khally92 · Answer

Irish boy123 thank you.

irishboy123 · Answer

is it this?


$$f(x,y)=cos\dfrac{1}{(y^2-x^2)^{1/2}}$$

with 

$$D= {(xy)|y>x} $$

sadly, that last bit does not make any sense to me  :-(

so i call upon the remarkable powers of @PartKohli

irishboy123 · Answer

@ParthKohli

parthkohli · Answer

I would say he means$$D= \{(x,y)|y>x\} 
$$Which really means that $y > x$ is a restriction on our domain.

parthkohli · Answer

Which is actually not absolutely correct, and it must be $|y| > |x|$ or something like that.   I don't see a harm in calling it $y^2 - x^2 > 0$.

parthkohli · Answer

|dw:1450475010877:dw|

irishboy123 · Answer

@khally92  ??

khally92 · Answer

Oh thank you so much  got it now really appreciate..

khally92 · Answer

P a r t h Koli sorry I awarded the medal to Irishboy123. But all thanks to you.