Day 77 – Friday, February 1
Algebra: Chapter 9, Lesson 1, p 400
Sets, Intersections and Unions
- A set is a well-defined collection of objects called members or elements
- Roster notation LISTS the members of the set.
- Set-Builder Notation gives a DESCRIPTION of how the set is built.
- The intersection of 2 sets A and B, written A ∩ B is the set of all members that are COMMON to both sets. We say ” A intersection B”.
- The union of 2 sets A and B, written A ∪ B is the set of all members that are in A or B or in both.
- If an intersection is EMPTY, we say the intersection is the empty set which is symbolized as ∅.
All of these concepts are described here too with examples!
Math-8, Chapter 6-9, p 317
Scientific Notation
Numbers expressed in scientific notation are written as the product of a factor and a power of 10. The factor MUST be greater than or equal to 1 and less than 10.
Count to the right to make the number come out as between 1 and 10 for numbers less than 0. Use a negative in the exponent for these numbers.
Count to the left to make the number come out as between 1 and 10 for numbers greater than 0. Use a positive in the exponent for these numbers.
Day 76 – Thursday, January 31
Algebra: Midterm EXAM, day #2
Math-8: Chapter 6-8, p 312
Geometric Sequences
A geometric sequence is a sequence in which the ratio between any 2 successive terms is the same. We did this lesson with Chapter 5, Lesson 9, arithmetic sequences. Just remember, geometric sequences have terms defined by multiplying or dividing by some term.
Day 75 – Wednesday, January 30Algebra: Midterm EXAM
Math-8: Chapter 6-7, p 308Solving Equations and Inequalities
We know how to do 1 step equations with addition/subtraction and multiplication/division. We do EXACTLY the same with inequalities. Remember, AGAIN, that multiplying or dividing by a NEGATIVE number, requires that we FLIP the SIGN of the inequality. Everything else stays exactly the same.