Slader consider an elastic string of length l whose ends are held fixed. the string is set in motion with no initial velocity from an initial position u(x, 0) = f(x). let l = 10 and a = 1 in parts (b) and (c). (a computer algebra system is recommended.)

The perimeter of a rectangular lot of land is 436 ft. this includes an easement of x feet of uniform width inside the lot on which no building can be done. if the buildable area is 122 ft by 60 ft, determine the width of the easement. select one: a. 9 feet b. 18 feet c. 4.5 feet d. 7 feet