∞ is a Greek word which generally means infinity in mathematics.
When describing an interval, only the upper bound is (-∞, x] (x ∈ r); Only the lower bound is [x, +∞) (x ∈ r); If there is neither upper limit nor lower limit, it is (-∞,+∞).
Why does the origin of infinite symbols mean that infinite symbols are horizontal?
The ancient Greek philosopher Arixtote (384-322 BC) believed that infinity could exist, because a finite quantity was infinitely separable and could not reach the pole, but infinity was universally acknowledged as unreachable.
/kloc-in the 20th century, a great Indian mathematician, Bascara, appeared, and his concept was close to that of modern theorization.
The symbol of putting 8 horizontally as ∞ to represent infinity was first put forward in john wallis's paper Arithmetic Infinity (published in 1655).
Mobius belt is usually regarded as the creative source of the infinite symbol "∞", because if someone stands on the surface of a huge Mobius belt and walks along the "road" he can see, he will never stop. But this is an untrue rumor, because "∞" was invented before Mobius belt.
Equation with Infinite Symbol In mathematics, two equations with infinite symbols are occasionally used, namely: ∞=∞+ 1, ∞=∞× 1.
A formula in which positive values represent infinity. There is no specific number, but positive infinity means a value greater than any number. The symbol is+∞, so is the symbol of negative infinity-∞.
Input Method 1: Sogou Pinyin Input Method
(1) Type "Wu Qiongda" (infinite)
(2) Press "CTRL"+"SHIFT"+"B"-Special Symbol-Math/Unit-Bottom line in the upper left corner is available, and click it (old version).
(3) In the second line of the second box, press "CTRL"+"SHIFT"+"V"-Math/Unit-the first, and click (sogou Input Method 7.6 Official Edition).
Two: QQ pinyin input method
(1) Enter "Fu Hao", press semicolon to open the symbol input device, and find ∞ in "Mathematics/Unit".
(2) Enter "v 1", press PageDown several times to find ∞, and press the letter before infinity to type ∞. Method 3: Press I to appear the menu, open the symbol input device, and find ∞ in "Mathematics/Unit".
(3) Enter "Infinite"
Three: If you want to input "∞", you can hold down the Alt key (shift key), press "4 1438" in the keypad in turn, and then release the Alt key to display "∞" on the screen.
Four: You can directly copy and paste "∞" in the corresponding position.
Five: Baidu input method
(1) Enter "Wu Qiong" (infinity).
(2) Settings, symbols, quantity/unit, and the last one in the second box table is ∞
Six: type it directly with the formula editor.