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- MATH PAK IV
-
- All material is (C) 1993 protected by Dan Dalal
- All Rights Reserved WorldWide.
- No Duplication and/or Modification allowed to this file.
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- Welcome to MATH 101, of MATH PAK IV. If you feel that this file is not
- in its entirety or there has been tampering done to the file, then you
- can send a blank, formatted disk(either 5.25 or 3.5") to :
-
- Dan Dalal
- Dept: MPK4
- 374 Don Basillo Way
- San Jose, CA 95123
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-
-
- MATH 101
-
- This file is intended for users who want a basic "re-fresh", or re-grasp of
- their original mathematical knowledge, held once upon a time...
-
- Questions are asked along the way, which you are encouraged to try. If you
- cannot solve a particular question, then go back and review the topic again
- and consult a more comprehensive math text, available at your school library
- or local public library. Or, talk with your math teacher or professor.
-
- You can exit from this by entering Alt-X. To make the view window larger
- or smaller, use the F5 key(if so equipped).
-
- ==============================================================================
-
- Some basic math symbols and terminology :
-
- Symbol Meaning
-
- + Addition process
- - Subtraction process
- x or * Multiplication process
- / or ÷ Division process
- < Less than
- > Greater than
- = Equals
- ≥ Greater than or equal to
- ≤ Less than or equal to
- ≈ Approximately
- √ Square root
- ∞ Infinity
- π Pi ≈ 3.1415
- Σ Summation process
- ± Plus or Minus
-
-
- What is an integer ?
- An integer, is a number that has no decimal parts to it. For example,
- an integer would be the number '2'. The numbers 3,222,-84, 325
- and 45 are all examples of positive and negative integer numbers.
-
- What is a real number ?
- A real number, is any number, regardless of it having a decimal(fraction)
- part or not. For example, a real number would be the number '3.43'. Notice
- that the number has a fractional part to it : .43 . Some real numbers may
- not always have a fractional part, like the number 68. This would imply
- that all INTEGER numbers can be considered a part of the real number world !
- The numbers -4.55, 34, -32.2, 3233.31 and 43.4 are all examples of positive
- and negative real numbers.
-
- The number line :
- You probably remember your math teacher in the second or third grade talking
- about this one ! A number line represents all real numbers, from negative
- infinity to positive infinity. Numbers to the left of the number 0, are
- called "negative numbers and have a negative sign(-) in front of the number,
- whereas numbers on the right side of the number 0, are called "positive"
- numbers and have a positive sign(+) in front of the number. When a sign is
- not present in front of a number, it can be assumed that the number is a
- positive(+) number.
-
- Here is an example of a number line :
-
- |-----|-----|-----|-----|-----|-----|-----|-----|
- ... -4 -3 -2 -1 0 1 2 3 4 ...
- negative positive
-
- Note that the point zero(0), is called the ORIGIN of the number line.
-
- Do you know what a RATIONAL number is ?
-
- A RATIONAL number, is any number which can be expressed as the quotient
- (the result of a division process) of two integers. For example, the
- fraction 4 / 3 is a rational number, as is 16 / 5.
-
- A IRRATIONAL number, is any number which cannot be express as the
- quotient of two integers.
-
- Give three examples of each of the following :
-
- a. integer
- b. real number
- c. rational number
- d. irrational number
-
- What does the symbol "<" mean ? Can you give an example ?
-
- Fractions.
- A fraction can be thought of as a way to do division. For example, given
- the fraction 3/4(3 over 4), aren't we actually saying we want to divide
- the number 3 by the number 4 ? By the way, the number "3" is on top of the
- fraction and the top number is called the NUMERATOR. The bottom number, "4"
- is called the DENOMINATOR, or :
-
- NUMERATOR
- __________
-
- DENOMINATOR
-
-
- Can you give three examples of a fraction ?
-
- Given the fraction 4/5, which number is the number is the numerator ?
- The denominator ?
-
- Square roots.
- The square root of a number, denoted by the symbol "√", means that
- we are trying to find a number, such that when that number is multiplied
- by itself, will equal the number we started with.
-
- When we see for example the expression √2, this tells us that we want
- to find a number, either positive or negative(because when a negative(-)
- and negative(-) are multiplied together, they equal a positive) that will
- give us a result of 2, which is under the √ symbol/sign.
-
- In this case, the √2(read "the square root of two"), would be ≈
- ± 1.414, or 1.414, -1.414( as -1.414 * -1.414 ≈ 2).
-
- What would the √1 = ?
-
- RULE : You cannot have(or calculate) the square root(√) of a NEGATIVE(-)
- number. Why this is, will be explained later...
-
- Absolute value.
- The absolute value of a number, denoted by two vertical marks(│) on
- the left and right side of a number, indicate the DISTANCE from that
- number to the ORIGIN, or point zero(0).
-
- For example, given │23│, this would indicate the distance(always a
- positive value) from the point "23" to the point(origin) 0, or 23.
-
- This also holds true for negative numbers. For example, given │-56│ ,
- this would indicate the distance from point "-56" on the number line
- to the point(origin) 0, or 56, so │-56│ = 56.
-
- What is │-3│ ?
-
- Basic Algebra.
- Algebra, in its simplest form, is the study of numbers and how they work
- with each other.
- We've so far talked about integers, real numbers, rational and irrational
- numbers, absolute value and fractions...All a part of Algebra !
-
- There are several properties that we can discuss here :
-
- 1. When we say "a < b", we mean that the value of "a" is less than
- the value of "b".
- 2. When we say "a > b", we mean that the value of "a " is greater(more)
- than the value of "b".
- 3. Given if a - b > 0, then a > b or b < a.
- 4. Given :
- a > b , this means that the point "a" is to the right of point "b"
- on the number line.
- a = b, this means that point "a" and point "b" are the same point
- on the number line.
- a < b, this means that the point "a" is to the left of point "b"
- on the number line.
- 5. If a,b and c are real numbers, then if
- a > b and b > c, then a > c
-
- if a < b and b < c, then a < c
-
- if a > b then a + c > b + c
-
- if a < b then a + c < b + c
-
- 6. Given " a ≥ b", then this means that point "a" is greater than or
- equal to the point "b" on the number line.
- 7. Given "a ≤ b", then this means that point "a" is less than or
- equal to the point "b" on the number line.
-
- 8. An open interval on a number line, can be denoted as (a,b), or
- we can say a < x < b, where x is the collection of all points between
- points "a" and "b". The points "a" and "b" are called "end points."
- 9. A closed interval on a number line, can be denoted as [a,b], or
- we can say a ≤ x ≤ b, where x is the collection of all points between
- points "a" and "b".
-
-
-
- Graphing.
- Mathematicians use what is called the Cartesian Coordinate System to
- do their graphing with. In the Cartesian Coordinate System, two
- mutually perpendicular number lines are used. The up-down(vertical)
- number line, is called the "y-axis" and the left-right(horizontal)
- number line, is called the "x-axis". We can show a small portion of it
- here :
-
- I
- I 4
- I
- I 3
- Quadrant II I Quadrant I
- I 2
- I
- I 1
- _____________________________x-axis
- -3 -2 -1 0 1 2 3 4
- I -1
- I
- I -2
- Quadrant III I Quadrant IV
- I -3
- I
- I y-axis
-
- Now, the point at which both lines meet, is called the ORIGIN and we
- can assign an ordered pair((a,b)) to the point as (0,0), where the
- first number is the "x" value and the second number, is the "y" value.
- Where the ordered pair lie on the plane, is called a "point".
- The first number, is also referred to as the "abscissa" of the point
- and the second number is referred to as the "ordinate" of the point.
-
- Some rules to remember :
- 1. If the ordered pair of numbers are both positive(+,+), then
- the point is in Quadrant I.
- 2. If the ordered pair of numbers are (-,+), then the point is
- in Quadrant II.
- 3. If the ordered pair of numbers are (-,-), then the point is
- in Quadrant III.
- 4. If the ordered pair of numbers are (+,-), then the point is
- in Quadrant IV.
-
- In what quadrant would the point (-45,56) be in ?
- What about the point (5,-2.3) ?
-
- Quadratic Equations.
- Quadratic equations can be given in the general form :
-
- ax² + bx + c = 0
-
- The Quadratic formula, can be given as :
-
- -b ± √(b² - 4ac)
- x = ___________________
- 2a
-
- The expression b² - 4ac, is called the "discriminant" and can determine
- the outcome of the roots of the quadratic function.
-
- Rules:
- 1. If the discriminant is > 0, then there are two real roots and
- the graph(a parabola) will intersect the x-axis at two points.
- 2. If the discriminant is = 0, then there is one real root and one
- root which is = (b) / (2a). The graph of the function will
- intersect the x-axis at only one point.
- 3. If the discriminant is < 0, then there are two imaginary roots
- and the graph of the function does not intersect the x-axis.
-
-
- Using the quadratic formula given above, can you solve for the following
- function : 4x² - 3x + 2 = 0 ? What are the two roots ? What does the
- discriminant tell you about the graph of this function ?
-
- Linear equations.
- Linear equations are equations that deal with first degree(x) polynomials
- and have as their graphs, straight lines on the Cartesian Coordinate System.
-
- The graph of a linear function, is a straight line.
-
- The "slope" of a line, can be given as the (change in y) / (change in x).
- The slope of a line is usually represented by the letter "m".
-
- m = (rise) / (run)
-
- or m = (y2 - y1) / (x2 - x1)
-
- For example, given two points on a line as (0,0) and (3,4), then :
- x1 = 0, x2 = 3, y1 = 0 and y2 = 4.
-
- Using the above formula, we get (4 - 0) / (3-0) or 4/3 = 1.33 as the
- slope of the line.
-
- Rules for slope :
- 1. if m > 0, the line slants upward from left to right.
- 2. if m = 0, then the line is parallel to the x-axis and the
- slope is undefined.
- 3. if m < 0, then the line slants downward from left to right.
-
-
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