首页学习工具公式参考

公式参考

常用数学和物理公式快速参考表。

Formula Reference

40 formulas

Algebra

Quadratic Formula

x = (-b ± √(b² - 4ac)) / 2a

Solves ax² + bx + c = 0

Algebra

Pythagorean Theorem

a² + b² = c²

Relationship in a right triangle

Algebra

Slope Formula

m = (y₂ - y₁) / (x₂ - x₁)

Slope between two points

Algebra

Distance Formula

d = √((x₂ - x₁)² + (y₂ - y₁)²)

Distance between two points

Algebra

Midpoint Formula

M = ((x₁ + x₂)/2, (y₁ + y₂)/2)

Midpoint between two points

Algebra

Binomial Theorem

(a + b)ⁿ = Σₖ C(n,k) aⁿ⁻ᵏ bᵏ

Expansion of (a+b)ⁿ

Algebra

Logarithm Properties

log_b(xy) = log_b(x) + log_b(y)

Product rule of logarithms

Geometry

Area of Circle

A = πr²

Area of a circle with radius r

Geometry

Circumference

C = 2πr

Circumference of a circle

Geometry

Area of Triangle

A = ½bh

Area of a triangle

Geometry

Volume of Sphere

V = ⁴⁄₃πr³

Volume of a sphere

Geometry

Volume of Cylinder

V = πr²h

Volume of a cylinder

Geometry

Volume of Cone

V = ⅓πr²h

Volume of a cone

Geometry

Surface Area of Sphere

A = 4πr²

Surface area of a sphere

Geometry

Law of Sines

sin(A)/a = sin(B)/b = sin(C)/c

Triangle side/angle relationship

Geometry

Law of Cosines

c² = a² + b² - 2ab cos(C)

Triangle side from angle

Calculus

Power Rule

d/dx [xⁿ] = nxⁿ⁻¹

Derivative of power function

Calculus

Product Rule

d/dx [fg] = f'g + fg'

Derivative of product

Calculus

Chain Rule

d/dx [f(g(x))] = f'(g(x)) · g'(x)

Derivative of composition

Calculus

Integration Power Rule

∫xⁿ dx = xⁿ⁺¹/(n+1) + C

Indefinite integral of power

Calculus

Fundamental Theorem

∫ₐᵇ f(x) dx = F(b) - F(a)

Connects derivative and integral

Calculus

Quotient Rule

d/dx [f/g] = (f'g - fg')/g²

Derivative of quotient

Calculus

Limit Definition

f'(x) = lim h→0 (f(x+h)-f(x))/h

Definition of derivative

Physics

Newton's Second Law

F = ma

Force equals mass × acceleration

Physics

Kinetic Energy

Eₖ = ½mv²

Energy of motion

Physics

Potential Energy

Eₚ = mgh

Gravitational potential energy

Physics

Einstein's Equation

E = mc²

Mass-energy equivalence

Physics

Ohm's Law

V = IR

Voltage = Current × Resistance

Physics

Speed of Wave

v = fλ

Wave speed = frequency × wavelength

Physics

Gravitational Force

F = G(m₁m₂)/r²

Newton's law of gravitation

Physics

Pressure

P = F/A

Pressure = Force / Area

Physics

Work

W = Fd cos(θ)

Work done by a force

Physics

Power

P = W/t

Power = Work / time

Chemistry

Ideal Gas Law

PV = nRT

Pressure × Volume = moles × R × Temperature

Chemistry

Molarity

M = n/V

Concentration = moles / volume (L)

Chemistry

pH Formula

pH = -log₁₀[H⁺]

Measure of acidity

Chemistry

Density

ρ = m/V

Density = mass / volume

Chemistry

Boyle's Law

P₁V₁ = P₂V₂

Pressure-volume relationship (constant T)

Chemistry

Heat Energy

q = mcΔT

Heat = mass × specific heat × temp change

Chemistry

Avogadro's Number

1 mol = 6.022×10²³ particles

Number of particles per mole