A combination counts selections where order does not matter — like picking 3 people for a committee. A permutation counts arrangements where order doe...

Correlation means two variables tend to change together — when one goes up, the other tends to go up (or down). Causation means one variable directly ...

A definite integral $\int_a^b f(x)\,dx$ evaluates to a number — it calculates the net signed area between a curve and the x-axis from $x = a$ to $x = ...

The mean is the arithmetic average (sum ÷ count). The median is the middle value when data is sorted. The mode is the value that appears most often. F...

Sine, cosine, and tangent are the three basic trigonometric ratios. In a right triangle: sine = opposite ÷ hypotenuse, cosine = adjacent ÷ hypotenuse,...

Both standard deviation and variance measure how spread out data is from the mean. Variance is the average of the squared deviations from the mean. St...