# Latest activity

• Otis replied to the thread Sin/Cos periodic 2*pi.
Yes, and we don't need periodicity for that. Many functions output the same value for different inputs. Here's an example: f(x) = x^4 +...
• HallsofIvy replied to the thread Sin/Cos periodic 2*pi.
You seem to be completely misunderstanding what a "function" is! You say "isn't [it] necessary for two function like sinx and...
• Yes, you have to convert the currencies to one standard, because their relative amounts determine the weighting of the average. For...
• ksdhart2 replied to the thread Match the post#.
0 + 1 + 234 + 5 \cdot 6 + 789 = 1052 9 \cdot 8 + 7 + 654 + 321 + 0 = 1052
• Denis replied to the thread Match the post#.
0! + 123 + 4 \cdot 5 \cdot 6 \cdot 7 + 89 = 1053 987 + 6 + 54 + 3 + 2 \cdot 1 + 0! = 1053 Phewwww......worked hard on that one too!!
• Otis replied to the thread Sin/Cos periodic 2*pi.
Hello Ryan$. It looks like you're sometimes mistyping the function's name sin as sinx. Also, I think it's best to use function... • HallsofIvy replied to the thread calculus. Neglecting air resistance, the only force here is the force of gravity which, at the surface of the earth, gives a vertical acceleration... • I would convert angles to radians, and write (using the Law of Sines)... • Ryan$ reacted to topsquark's post in the thread Sin/Cos periodic 2*pi with Like.
HallsofIvy had a good post. The way the function sin(x) is defined makes it periodic. If you go around the unit circle once (an angle...
• Ryan\$ replied to the thread Sin/Cos periodic 2*pi.
So we can have the same function with two different argument ? like sinx=sinx(x+180) and that's why called periodic? I mean periodic...
• I have no idea what "superposition" means here. Are these "v"s vectors and you are referring to vector addition?
• It doesn't seem to work in any case. Using a + b = 1 try out a = 2. Your expression is negative. If a \neq b then try a = 2, b = 3...
• topsquark reacted to MarkFL's post in the thread Telescoping sums with Like.
Okay, having proved the given identity, then we know...
• topsquark reacted to Denis's post in the thread where did this term go? with Like.
Become an "expert": https://www.mathsisfun.com/algebra/completing-square.html
• topsquark replied to the thread Sin/Cos periodic 2*pi.
HallsofIvy had a good post. The way the function sin(x) is defined makes it periodic. If you go around the unit circle once (an angle...