if the first three fibonacci numbers are given as x1=1, x2=1 and x3=2, what is the value of n for which xn+xn+1=55

Find the volume of the solid whose base is the region bounded by f(x), g(x) and the x-axis on the interval [0, 1], and whose cross-sections perpendicular to the y-axis are squares. your work must show the integral, but you may use your calculator to evaluate it. give 3 decimal places for your answe