Name 5 main maths formulae.?

Question

throughout the world OR a maths formula or two, which you found important throughout highschool.

EDIT: I am currently in Year 9 In Australia.
Pythagoras is definitely one and F= M*A
PLease keep posting and thankyou to those who did.

Answer 1

Here are a few that come to mind.

Newton's Law: F = M*A This one equation, in various forms, is the basis for most of classical physics.

Einsteins Equivalence of Mass and Energy: e = mc^2. This equation is a cornerstone of relativity and used heavily in all of the nuclear sciences.

Pythagorean Theorm: a^2 = b^2 + c^2 - 2bc*cos(A). This is the general form of the equation, and allows for the solution of triangles, important in so many ways.

Compound Interest Formula: P = Po(1+i)^n This is the basic formula for calculating compound interest, and is the basis for much of the banking and finance industry.

Hope this helps,

-Guru

Answer 2

Math formulae important in high school:

Well, pythagorean thm, of course.

Basic Trigonometric identities:
cos^2 + sin^2 = 1 (that was very useful, and also pythagorean!)

f'(x) = lim as h->0 ( f(x+h) - f(x) ) / (x-h)
(Very useful on the AP Calc exam, that one.)

Also, I found it EXTREMELY useful to have the decimal equivalents of a lot of fractions memorized. Not sure how many times that proved helpful:
1/7 = .142857142857...
1/11 = .090909090909...
1/6 = .16666666....

Also, frequently handy (but more often in adult life, answering questions from kids) is that there are 86400 seconds in a day (that one's come in handy a LOT).

Oh, and for very small theta, sin(theta)=theta... That's also been handy (but not so much in high school).

Answer 3

The quadratic formula

The Pythagorean Theorem

The Pythagorean Trigonometric Identities

The Fundamental Theorem of Calculus

The Cauchy Criteria

Euler's equation which leads tothe famous e^i*pi =-1

Answer 4

pythagorean thereom and special right triangle ratios
Heron's formula and 1/2 ab sin c, whatever that's called
this isn't really a formula but...... pascal's triangle
the formulas for the sum of the first n numbers, the nth triangular number, the sum of the 1st n squares, the sum of the 1st n cubes, etc.
3sqrt3s^2/2, the formula for the area of a hexagon
etc., etc.................
I'm not in high school but my math is about 10th-11th grade, so.....

Answer 5

The distance formula for points on the xy-plane.

The midpoint formula

The quadratic formula

The distance formula for traveling: D = rt

Simple interest formula: I = PRT

The six basic trig functions

Pythagorean theorem

Guido

Answer 6

Pythagorean theory
quadratic formula
binomial formula
area of a circle
equation of a line, y = mx+b

Answer 7

volumes
cylinder= pie*r^2*h
cone= 1/3*pie*r^2*h
cube= bhw
rectangular prism= bhw
and cant for get a^2+b^2=c^2

probly not what u want though
im only in 8th grade
but i am taking 9th grade math

Answer 8

Pythagoras' theorem: a^2 + b^2 = c^2
Distance formula: ((x2 - x1)^2 + (y2 - y1)^2)
Trig Identities: sinx^2 + cosx^2 = 1
sin(a + b) = sina*cosb + cosa * sinb
cos(a + b) = cosa*cosb - sina*sinb

Answer 9

addition
subtraction
multiplication
division