THE COMPOUND · THE KIT

The Formula Board

Every rule the plots and drills lean on. One board, no guessing.
Quadratic formulax = −b ± √(b2 − 4ac)2a solves any quadratic set equal to zero.
Discriminantb2 − 4ac. Positive: two real roots. Zero: one. Negative: none real.
Completing the squareTake half the middle coefficient, square it, add it to both sides.
Function notationf(x) is the machine’s output when x goes in.
Domain and rangeDomain is what may go in. Range is what can come out.
Compositionf(g(x)): run the inner machine first, feed its output to the outer.
Inverse functionsSwap x and y, then solve for y again. The inverse undoes the original.
Rational exponentsA fraction in the exponent names a root: the bottom is the root, the top is the power.
Simplifying radicalsPull every perfect square out from under the root sign.
Imaginary uniti2 = −1. The unit that opens the complex numbers.
Logarithmlogb x asks: b to what power gives x?
Exponential growthy = abx. A base above one grows; below one, it decays.
Circle equationx2 + y2 = r2, centered at the origin.
Arithmetic sequenceAdd the same difference at every step.
Geometric sequenceMultiply by the same ratio at every step.
Systems of threeEliminate one letter to get two equations, then eliminate again.