Signs that a listener is paying attention include:

Why were most movies from the late 1890s until the early 1930s only filmed in black and white? there were only a few people who could afford the technology to produce color motion pictures back then. audiences did not want color motion pictures until later. the film used to make color motion pictures often overheated, which was a safety hazard, so it was generally not allowed. color films had to be hand-colored, frame by frame.

Consider the series where in this problem you must attempt to use the ratio test to decide whether the series converges. compute enter the numerical value of the limit l if it converges, inf if it diverges to infinity, minf if it diverges to negative infinity, or div if it diverges but not to infinity or negative infinity.

Answer these and get 40 points and brainliest