Monday, March 19, 2012

12th March, 2012: How do we calculate the area of rectangles and triangles?

Area is defined as the number of square units that covers a closed figure. [iCoachMath]

You find the area of shapes like rectangles and triangles by using different formulas for both. For example, to find the area of a rectangle, you multiply the base times the height. For a triangle, there's a conjecture that says:
The area of a triangle is given by the formula A= 1/2(BxH), where A is the area, B is the base, and H is the height.

5th of March, 2012: How do we find the locus of points?

The locus is the set of all points that satisfy a given condition. It is a general graph of a given equation.

There are five locus theorems:

  1. One point: A circle with the original point at its center.
  2. Two fixed points: The locus of points equidistant from two points is the perpendicular bisector of the line segment connecting the two points
  3. One line: the locus of points equidistant from a line are two lines, on opposite sides, and equidistant and parallel to that line
  4. Two parallel lines: A line through the middle of the two lines
  5. Two intersecting lines: Two intersecting lines half-way between the two original points

28th February, 2012: What is a mathematical statement?

A mathematical statement is a statement that can be judged to be true or false.

There are three types of mathematical statements:
A conditional: The most frequently used statement in the construction of an argument or in the study of mathematics.
Ex: If the two angles are congruent, then the two angles are both right angles.

An inversea conditional statement is formed by negating the hypothesis and negating the conclusion of the original statement. [Regents Prep]
Ex: If the two angles are not congruent, then the two angles are not right angles.

A contrapositive: Negating and switching the hypothesis and conclusion.
Ex: (Normal sentence): If Lisa sells her house, then her income did not stay the same.
Contrapositive: If Lisa's income stays the same, the she will not sell her house.