The fibonacci sequence is a mathematical sequence which occurs throughout nature as well as in music, art and popular culture. the fibonacci sequence are the following numbers in the integer sequence 0,1,1,2,3,5,8,13,21,34,55,89. . the definition for fibonacci sequence is as follows, fn=fn-1 + fn-2 where f0=0,f1=1 write a function named fibonacci which takes one input x which is a non-negative integer(s) and returns the xth fibonacci number in the fibonacci sequence. if x is a vector or matrix, the output is a vector or matrix of the same size as the input with fibonacci numbers of the corresponding elements of the input.