34. [Tech] Scherk's surface is given by the equation ez cosy = cosx. a. Use a computer to graph a portion of this surface. b. Verify that Scherk's surface is a minimal surface.\fA surface tbat has the least surface area among all surfaces with a given boundary is called a minimal surface. Soap bubbles are naturally occurring examples of minimal surfaces. It is a fact tbat minimal surfaces baving equations of the form 2 = f(x, y)(wbere f is of class C2) satisfy tbe partial differential equation (6)