Answer: She spend $1.20 for lunch.
Step-by-step explanation:
Let the total amount be 'x'.
Half of her money spend for lunch be
Half of her money left for a movie be
Amount she has now = $1.20
So, According to question, it becomes ,
Hence, Amount she spend for lunch is
Therefore, she spend $1.20 for lunch.
c(x)=9x+89
I know that you don't have the answer listed, but it is the correct answer.
Answer:
It is proved that exixts at (0,0) but not differentiable there.
Given function is,
exists.
And,
where m is a variable.
which depends on various values of m, therefore limit does not exists. So f(x,y) is not continuous at (0,0). Hence it is not differentiable at (0,0).