Which of the following statements is trueSelect one:O " ("f(x, y)dxdy gives the area of the graph of f(x. y) above a rectangular region in xy-plane.O If f(x, v. 2) = x² + y? - - xyz + 2. then f(x, y. z) =f(2. y. x),O if f(x, y, 2) = x² + y² - z? - xyz + 2, then f(x. y. ) = f(.x.2)O If f(x, y) is constant functionof y, then = 0

Third option is true f(x, y, z) = f(y, x, z)

Which of the following statements is true Select one: O " "Sx, y)dxdy gives the area of the graph of f(x. y) above a rectangular region in xy-plane. O if f(x, y, 2) = x + y --xyz + 2. then f(x, y. 2) = f(2. y. ), O tfx. y. 2) =x +y - - xyz + 2. then fCx. y. z - /0. x.2) %3! O if f(x. y) is constant functionof y, then -0

Which of the following statements is true Select one: O " "Sx, y)dxdy gives the area of the graph of f(x. y) above a rectangular region in xy-plane. O if f(x, y, 2) = x + y --xyz + 2. then f(x, y. 2) = f(2. y. ), O tfx. y. 2) =x +y - - xyz + 2. then fCx. y. z - /0. x.2) %3! O if f(x. y) is constant functionof y, then -0