Evaluate Expression: To solve for z, we need to evaluate the expression given by z=x2+y2−4+ln(xy). We will start by simplifying the square root and the natural logarithm separately.
Simplify Square Root: First, let's consider the square root part: x2+y2−4. This expression represents the distance from the origin to the point (x,y) in a Cartesian plane, with a correction of −4 inside the square root. We cannot simplify this further without specific values for x and y.
Simplify Natural Logarithm: Next, we look at the natural logarithm part: ln(xy). The natural logarithm of a product is the sum of the logarithms of the individual factors, so ln(xy)=ln(x)+ln(y). However, we cannot simplify this further without specific values for x and y.
Combine Parts: Now, we combine the two parts we have evaluated: x2+y2−4 and ln(xy). The expression for z is simply the sum of these two parts, which cannot be simplified further algebraically.
Consider Domain: We must also consider the domain of the function for z. The expression inside the square root, x2+y2−4, must be greater than or equal to 0 for the square root to be real. Additionally, the product xy must be positive for the natural logarithm to be real, since the logarithm of a non-positive number is undefined.