(Tuesday) We finished testing on Tuesday, May 15th! Hooray!! Today was the last work day to catch up on missing assignments.
Pre-Algebra: Chapter 12-1 (Wednesday)
Area: Parallelograms, Triangles and Trapezoids
- The are of a rectangle is the length * width or `l * w`.
- A parallelogram is a rectangle sometimes pushed to one side. The area of a parallelogram is then `b * h` where b is the base and h is the height. The height and the base MUST be perpendicular to each other.
- The area of a triangle is `(1/2)(b * h`) where b is the base again and h is the height. Again, the base and the height must be perpendicular.
- A trapezoid has 2 bases, one is `b_1` and the other is `b_2`. Again, a trapezoid has a height perpendicular to the 2 bases. The formula for the area of a trapezoid is `(1/2)(h)(b_1 + b_2)`
Remember, the base of a triangle can be any side, just make sure that the height is perpendicular! The same is true for a parallelogram, don’t use the slant height, it must be perpendicular. In a trapezoid, the bases MUST BE PARALLEL!
Algebra: Chapter 12-1 and 12-2
Relations and functions and graphs
- A relation is a set or ordered pairs. The domain of a relation is the set of first coordinates (the x’s). The range is the set of second (or y) coordinates.
- A function is a relation that assigns one member of the domain EXACTLY one member of the range. In other words, one x can have ONLY one y value.
You can evaluate a function `f(x) = 2x^2 + 5` for `f(2)` by substituting 2 for every x that you see. In our example then, `f(2)=2*2^2 +5=13`
You can recognize a function with the vertical line test. You can find the domain and range of a function by seeing where the function is not defined. Good examples are `sqrt(−)`, we can’t take square roots of negative numbers and we cannot have `1/0` because that results in infinity or an undefined solution.
Here again, is a great link for Purplemath!