Math formulas

Linear equation

y=mx+b (m=rate of change, b=y-intercept)

Linear function for revenue

R(x)=ax (a=price, x=# sold)

Cost

C(x)=mx+b (m=marginal cost, b=fixed cost)

Profit

P(x)=R(x)-C(x) (R(x)=revenue, C(x)=cost)

Demand

q(p)=mp+b (m=change in demand per unit change in price, p=price, b=demand price for 0, usually negative slope)

Supply

q(p)=mp+b (m=change per unit of price increase, b=initial supply w/o demand, p=price, usually positive slope)

Quadratic formula

f(x)=ax²+bx+c

Vertex x-coordinate/x-intercept given there is 1

-b/2a

Vertex y-coordinate

f(-b/2a)

Discriminant (quadratics)

delta=b²-4ac

x intercept given there are 2

-b±sqrt delta / 2a

Quadratic function for revenue

R=P*Q (p=price, q=quantity (usually x))