# Mathematics for Technology I (Math 1131)

Durham College, Mathematics
Free
• 55 lessons
• 1 quizzes
• 10 week duration
• ##### Numerical Computation

Here you'll be introduced to the bare basics of mathematics. Topics include commonly used words and phrases, symbols, and how to follow the order of operations.

• ##### Measurements

An introduction to numerical computation. Emphasis is placed on scientific and engineering notation, the rule of significant figures, and converting between SI and Imperial units.

• ##### Trigonometry with Right Triangles

Here we focus on right angle triangles within quadrant I of an x-y plane. None of the angles we evaluate here are greater than 90°. A unit on trigonometry with oblique triangles is covered later.

• ##### Trigonometry with Oblique Triangles

This unit is a continuation of trigonometry with right triangles except we'll extend our understanding to deal with angles *greater* than 90°. Resolving and combining vectors will be covered at the end of this unit.

• ##### Geometry

This unit focuses on analyzing and understand the characteristics of various shapes, both 2D and 3D.

## Mathematics for Technology I (Math 1131)

### Numerical Operations

A numerical operation can be described as an action or process used to solved a numerical problem.

If you have two numbers x and y, the following rules apply when these numbers are being added or subtracted.

• Rule of Signs for Addition:   (xy) is the same as x + (–y)  or  x – (+y) because a negative beside a positive (or vice versa) always make a negative.
• Rule of Signs for Subtraction:   x + y is the same as x – (–y) because two negatives side-by-side make a positive.

Here are a few examples:

For #1, the answer is clearly 9. But you could also have gotten 9 if you had:   7  (2) because of the rule of signs for subtraction.

For #2, the answer is 5. But you could also have gotten 5 if you had:   9 + (–4) or 9 – (+4) because of the rule of signs for addition.

For #3, the answer is –2.

A summary of these symbols is shown below:

More examples:

#1:   14

#2:  –2

#3:   18

[collapse]

Multiplying and Dividing Signed Numbers

• Rules of Signs for Multiplication:
• (+x)(+y) = (–x)(–y) = +xy
• (+x)(–y) = (–x)(+y) = –xy
• It’s also important to note that the same rules apply for division too.

Multiplication of two or more factors can be symbolized in 3 main ways:

For division:

Here are a few examples: