Revision as of 19:00, 6 January 2020

Memorize

These are things you need to memorize.

Order of operations: first parenthesis, then exponents, then multiplication/division/modulus, then addition and subtraction. And left to right.
Powers/exponents
- 2¹⁰ = 1024, roughly 1 thousand
- 2^a+b = 2^a * 2^b
- y^a+b = y^a * y^b
- 2^-a = 1 / (2^a)
- 2²⁰ = 1024 × 1024, roughly 1 million
- 2³⁰ = 1024 × 1024 × 1024, roughly 1 billion
Logarithms
- log_bx = y, means by = x, for any b > 1
- log_bx = log_cx / log_cb, for any b > 1, c > 1
- log₂10 is about 3.32
- log_b(xy) = y log_b x, for any b > 1

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-Miscellaneous
+=Memorize=
+These are things you need to memorize.
-Order of operations: first parenthesis, then exponents, then multiplication and division, then addition and subtraction.  And left to right.
+* ''Order of operations:'' first parenthesis, then exponents, then multiplication/division/modulus, then addition and subtraction.  And left to right.
+* ''Powers/exponents''
-Powers/exponents
+** 2<sup>10</sup> = 1024, roughly 1 thousand
-<sup>10</sup> = 1024, roughly 1 thousand
+** 2<sup>a+b</sup> = 2<sup>a</sup> * 2<sup>b</sup>
-a+b = 2a × 2b
+** y<sup>a+b</sup> = y<sup>a</sup> * y<sup>b</sup>
-ya+b = ya × yb
+** 2<sup>-a</sup> = 1 / (2<sup>a</sup>)
--a = 1 / (2a)
+** 2<sup>20</sup> = 1024 × 1024, roughly 1 million
-= 1024 × 1024, roughly 1 million
+** 2<sup>30</sup> = 1024 × 1024 × 1024, roughly 1 billion
-= 1024 × 1024 × 1024, roughly 1 billion
+* ''Logarithms''
-Logarithms
+** log<sub>b</sub>x = y, means by = x, for any b > 1
-logbx = y means by = x
+** log<sub>b</sub>x = log<sub>c</sub>x / log<sub>c</sub>b, for any b > 1, c > 1
-logbx = logcx / logcb
+** log<sub>2</sub>10 is about 3.32
-log210 is about 3.32
+** log<sub>b</sub>(xy) = y log<sub>b</sub> x, for any b > 1
-logb(xy) = y logb x