• Game Theory: A field of mathematics that studies patterns in order to make predictions about the future.”-Origin by Dan Brown.

• Calculus: Latin for "a pebble used for counting."

Commutative law of multiplication: a × b = b × a,

variables, and they are what truly distinguishes algebra from arithmetic.

i² = –1 really means. If we multiply a positive number by i², the corresponding arrow rotates 180 degrees, flipping from east to west, because the two 90-degree rotations (one for each factor of i) combine to make a 180-degree rotation.

fractal—an intricate shape whose inner structure repeated at finer and finer scales.

•equal sign, =, is formed by two parallel lines because, as its originator, Welsh mathematician Robert Recorde, wrote in 1557, “no two things can be more equal.”

•Alternating harmonic series: 1 – 1/2 + 1/3 – 1/4 + 1/5 – 1/6 + …

Calculus:Latin for "a pebble used for counting."

vector calculus, the branch of math that describes the invisible fields all around us. Think of the magnetic field that twists a compass needle northward, or the gravitational field that pulls your chair to the floor, or the microwave field that nukes your dinner.-Joy of X by Strogatz.

vectors. They show two kinds of information: a direction (which way to move that foot) and a magnitude

the divergence of a vector field measures: how fast the area of a small circle of corks grows.

The other kind of derivative measures the curl of a vector field. Roughly speaking, it indicates how strongly the field is swirling about a given point.

one of the central lessons of statistics—things that seem hopelessly random and unpredictable when viewed in isolation often turn out to be lawful and predictable when viewed in aggregate.-Joy of X by Strogatz.