Assallamulikum Sir, Conversion (59)10 into binary 59/2=28-1 ? 28/2=14-0 14/2=7-0 7/2=3-1 3/2=1-1 (111001) ?

AoA, Sir if you may plz explain “replace the part of curve between the points A(x_n, f(x_n)) and B(x_n-1, f(x_n-1)) by a chord in the interval” . diagrammatic explanation will be a great help in comprehension of the subject matter. Thanks