What is a variable? Why is it helpful in programming?

Robots with telescoping arms are sometimes used to perform tasks (e. g., welding or placing screws) where access may be difficult for other robotic types. during a test run, a robot arm is programmed to extend according to the relationship r = 3 + 0.5cos(4θ) and the arm rotates according to the relationship θ=−π4t2+πt , where r is in feet, θ is in radians, and t is in seconds. use a computer program to plot the path of tip a in x and y coordinates for 0 ≤ t ≤ 4s.

These statements describe lists in presentation programs: a. bullets can be turned off and on. b. bullets cannot be turned off. c. bullet styles, colors, and sizes can be changed. d. lists don't have to use bullets or numbers. e. numbering styles, colors, and sizes can be changed. f. numbers can be turned off and on. g. numbers cannot be turned off. select all that apply

Fast answer i need for apex ! smartphones should be banned from the classroom in public schools so that students cannot cheat on test so easily? which is an example of a counter argument to the thesis above? a. the classroom is a place for learning not for making phone calls b. smartphones are useful learning tools in the modern classroom c. banning smartphones will not students pay attention to teachers any better d. banning smartphones would decreased incidents of theft