2.3 Circles

Equation of a Circle: MPM2D Grade 10 Mathematics

1. Introduction to the Equation of a Circle

A circle is a set of all points in a plane that are at a fixed distance (called the radius) from a fixed point (called the center). The standard form of the equation of a circle depends on the location of its center.

1.1. Equation of a Circle with Center at the Origin

If the center of the circle is at the origin (0,0), the equation of the circle is:

\[ x^2 + y^2 = r^2 \]

Example:

Consider a circle with a radius of 5 units centered at the origin.

The equation is:

\[ x^2 + y^2 = 5^2 \]

\[ x^2 + y^2 = 25 \]

2.2- Length of a Line Segment

2.2 Length of a Line Segment

1. What is the Distance Formula?

The distance formula is used to determine the distance, \(d\), between two points in the Cartesian plane. If the points are \(A(x₁,y₁)\) and \(B(x₂,y₂)\), the distance between them is given by:

\[d = \sqrt{{(x_2- x_1 )^2+ (y_2- y_1 )^2 }}\]

2. How to Find the Length of a Line Segment?

The length of a line segment is the distance between its endpoints. So, you can use the distance formula to find the length of a line segment. If the endpoints of the line segment are \(A(x₁,y₁)\) and \(B(x₂,y₂)\), the length of the line segment is:

\[length = \sqrt{{(x_2- x_1 )^2+ (y_2- y_1 )^2 }}\]

Naming Organic Compounds

Naming Organic Compounds: A Guide for SCH4U Course

Naming Alkanes with and without Branches

Alkanes are hydrocarbons with only single bonds. The general formula for alkanes is \(C_nH_{2n+2}\).

Unbranched alkanes are named based on the number of carbon atoms in the chain: Methane (1 carbon), Ethane (2 carbons), Propane (3 carbons), Butane (4 carbons), Pentane (5 carbons), Hexane (6 carbons), Heptane (7 carbons), Octane (8 carbons), Nonane (9 carbons), Decane (10 carbons).

2.1 Analytical Geometry- Mid point

2.1 Mid-point and Length of a Line Segment

1. What are coordinates of a point in the Cartesian plane?

The Cartesian plane, also known as the coordinate plane, is a two-dimensional plane formed by the intersection of a vertical line (y-axis) and a horizontal line (x-axis). These lines are perpendicular and intersect at the origin, forming four quadrants.

A point in the Cartesian plane is represented by an ordered pair of numbers \((x,y)\), where ‘x’ is the distance from the point to the y-axis (x-coordinate), and ‘y’ is the distance from the point to the x-axis (y-coordinate).

2. What is the midpoint of a line segment?

The midpoint of a line segment is the point that divides the line segment into two equal segments. It is exactly halfway between the endpoints of the line segment.

1.6 System of Linear Equations

1.6 Solving Systems of Equations by Elimination Method

The method of elimination is a technique used to solve systems of linear equations. This method involves adding or subtracting the equations to eliminate one of the variables. Here’s a step-by-step process:

Step 1: Write Down the System of Equations

Write down the system of equations that you want to solve. For example, let’s consider the following system of equations:

\(2x + 3y = 12\)

\(4x - 3y = 6\)

1.5 System of equivalent Equations

1.5 Equivalent Equations

1.5.1) Equivalent Equations with Two Variables

Equivalent equations with two variables are equations that have the same set of solutions. For example, the equations \(2x + 3y = 6\) and \(4x + 6y = 12\) are equivalent because they represent the same line in the coordinate plane, and thus have the same set of solutions.

1.4 Solving system of linear equations by substitution

1.4 Solving by Substitution

To solve a system of linear equations by using substitution includes the following steps.

Consider we have system of equations as:

\(x + y = 10\) and \(2x + 3y = 8\)

Step 1: Isolate one of the variables in one of the equations

Choose one of the equations (any of the variables having coefficient as ‘1’) and solve it for one variable in terms of the other. This can be either x or y. For example, if you have the equation \(x + y = 10\), you can isolate \(x\) by subtracting \(y\) from both sides to get \(x = 10 - y\).