Equation 10 · Part 12 · The Machine Before Electronics
Ending index or upper bound: t
What this part means
This label says where the repeated addition, multiplication, or accumulation stops. It sets the last term or end of the range.
Its job in the formula
t occurs below the fraction bar. The quantity above the bar is divided by this expression; zero is excluded as a denominator.
Full expression→Ending index or upper bound: t→Article meaning
The passage around this formula
Summation is the easy operation to build. Integration is the one that opens up a whole class of problems, and the mechanism that made it practical was the wheel-and-disc integrator: a wheel riding on a rotating disc at a radius that can be varied, so that the wheel’s rotation accumulates the product of the disc’s rotation and the instantaneous radius. If the disc rotation represents the independent variable and the radial position represents the dependent one, the wheel angle represents . which is to say, the integral of y with respect to x , produced continuously and without arithmetic.
Learn the underlying idea
Σ adds a collection of terms. Π multiplies them. The lower and upper labels tell you which terms belong to the collection.
Open the illustrated sums and products: repeat an operation over an index guide →
See this notation across published equations →
Sources cited in the article section
These citations provide research context; check each source for the exact claim it supports.