Page 623 - Ultimate Visual Dictionary (DK)

USEFUL DATA

RULES OF ALGEBRA MATHEMATICAL SYMBOLS
EXPRESSION COMMENTS EXPRESSION BECOMES SYMBOL EXPLANATION
a + a Simple addition 2a + addition
a + b = c + d Subtract b from either side a = c + d - b - subtraction
ab = cd Divide both sides by b a = cd ÷ b × multiplication
(a + b) (c + d) Multiplication of bracketed terms ac + ad + be + bd ÷ division
a 2 + ab Use parentheses a(a + b) = equals
(a + b) 2 Expand terms in parentheses a 2 + 2ab + b ≠ does not equal
2
a 2 —b Difference of two squares (a + b)(a-b) > greater than
2
1/a + 1/b Find common denominator (a + b)/ab < less than
a/b ÷ c/d Dividing by a fraction is the same a/b × d/c ≥ greater than or equal to
as multiplying by its reciprocal ≤ less than or equal to
∞ infinity
POWERS OF TEN USED WITH SCIENTIFIC UNITS % percent
π pi (3.1416)
FACTOR NAME PREFIX SYMBOL
° degree
10 18 quintillion exa- E ≈ is approximately equal to
10 15 quadrillion peta- P ∠ angle
10 12 trillion tera- T ∏ parallel to
10 9 billion giga- G ∑ summation
10 6 million mega- M u, u vectors
10 3 thousand kilo- k f(x) function
10 2 hundred hecto- h ! factorial
10 1 ten deca- da √ square root
10 -1 one-tenth deci- d ξ universal set
10 -2 one-hundredth centi- c A ∩ B intersection
10 -3 one-thousandth milli- m A ∪ B unison
10 -6 one-millionth micro- u A ⊂ B subset
10 -9 one-billionth nano- n Ø null set
10 -12 one-trillionth pico- p
10 -15 one-quadrillionth femto- f
10 -18 one-quintillionth atto- a
CHEMISTRY SYMBOLS
Note: The American system of numeration PHYSICS SYMBOLS
for denominations above one million is used SYMBOL MEANING
in this book. In this system, each of the SYMBOL MEANING + plus; together with
denominations above one billion (1,000 α alpha particle − single bond
millions) is 1,000 times the preceding one. β beta ray • single bond; single
γ gamma ray; photon unpaired electron; two
ε electromotive force separate parts or
BIOLOGY SYMBOLS η efficiency; viscosity compounds regarded
λ wavelength as loosely joined
SYMBOL MEANING μ micro-; permeability = double bond
ο female individual ν frequency; neutrino ≡ triple bond
(used in inheritance charts) ρ density; resistivity R group
male individual σ conductivity X halogen atom
(used in inheritance charts) c velocity of light Z atomic number
female e electronic charge
male
× crossed with; hybrid
+ wild type SCIENTIFIC NOTATION
F 1 offspring of the first NUMBER NUMBER POWER OF TEN SCIENTIFIC
generation BETWEEN 1 AND 10 NOTATION
offspring of the second
F 2 10 1 10 1 1 3 10 1
generation
150 1.5 10 2 (= 100) 1.5 3 10 2
274,000,000 2.74 10 8 (= 100,000,000) 2.74 3 10 8
TEMPERATURE SCALES 0.0023 2.3 10 -3 (= 0.001) 2.3 3 10 -3
To convert from Fahrenheit (F) to Celsius (C): C = (F—32) × 5 ÷ 9
To convert from Celsius to Fahrenheit: F = (C × 9 ÷ 5) + 32
To convert from Celsius to Kelvin (K): K = C + 273 TRIGONOMETRY
To convert from Kelvin to Celsius: C = K - 273
Angle A sin A cos A tan A
(degrees)
0 0 1 0
30 1/2 √3/2 1/√3
Celsius -20 -10 0 10 20 30 40 50 60 70 80 90 100 45 1/√2 1/√2 1
Fahrenheit -4 14 32 50 68 86 104 122 140 158 176 194 212 60 √3/2 1/2 √ 3
Kelvin 253 263 273 283 293 305 313 325 333 343 353 363 373 90 1 0 ∞

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