D) It modernized farms and rural areas
Hope I helped :)
Answer: Persistence of vision.
Explanation:
The persistence of vision was described the first time by Peter Mark Roget.
Explain t<em>he ability of the retina to maintain an image a third of a second after viewing it, even when the image passed quickly.</em> This allows the brain to analyze and process the image. Due to this process, the visual information is processed continuously, much like a movie, instead of having pauses between images.
<em>I hope this information can help you.</em>
Cos(pi/2 - x) = sin(x). sec(x) = 1/cos(x), so the left side would be sinx/cosx = tanx. So it checks out.
