# 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)

### Cosine Law

To use the sine laws introduced last section, we need to know at least one complete side length to angle ratio including another known side length or angle. Sometimes we may not have that information, but instead you’re given all three side lengths and no angle. In this case, we can still solve such a triangle using the cosine law. The formulas you’ll need are shown below:

We use these formula under these conditions:

• Side – Angle – Side (AAS)
• Side – Side – Side (SSS)

• Sometimes to solve a triangle, you may have to use both the cosine law and sine law.

Let’s look at a few examples where the cosine law is used to solve triangles.

The purpose of learning these laws is to apply it to real-life. The two videos below will show two separate application problems pertaining to the cosine law.