Help is greatly needed

To find the extreme values of a function f(x. y) on a curve x-x(t), y y(t), treat f as a function of the single variable t and use the chain rule to find where df/dt is zero. in any other single-variable case, the extreme values of f are then found among the values at the critical points (points where df/dt is zero or fails to exist), and endpoints of the parameter domain. find the absolute maximum and minimum values of the following function on the given curves. use the parametric equations x=2cos t, y 2 sin t functions: curves: i) the semicircle x4,y20 i) the quarter circle x2+y-4, x20, y20 b, g(x, y)=xy

Which expressions are equivalent to k/2 choose 2 answers: a k-2 b 2/k c 1/2k d k/2 e k+k

If a || b and b | y, then ? a) x || y. b) x | a. c) a | y. d) a || y.