11/20/13

Homework: Ch. 6.1 #7-27 odds, 41

Can you factor this? 6x² + 11x + 3

Sure, you can do it algebraically, but you can also channel your inner ancient Greek and solve it using geometry. See drawing at bottom.
The answer is (3x + 1)(2x+3).

Ratios are comparisons between two like units. For instance, in this class, the ratio of males to females is 11:14 (that's in colon notation. There are no units because they cancel out.)
Rates are fractions that compare two unlike units. Ex: 30 miles/hour, 3 dollars/pound, etc.
If they can be reduced, reduce them. Don't leave any radicals in the denominator. Write them as fractions!

Proportions are equations where a rate equals a rate, or a ratio equals a ratio. You can cross-multiply to get your answer with proportions. Ex: 30 miles/hour = x miles/5 hours. (x = 150)

Practice problems:
If 8,218 schools have 270,272 girls, what is the rate of girls per school? Round answers to the nearest tenth.
Answer: 270,272 girls/ 8218 schools = 32.9 girls/school.

3,122 people smoke cigarettes. 1,615 of those people quit smoking. What is the ratio of those that smoke to those that don't?
Answer: 3,122 - 1,615 = 1,507 smokers left. The ratio of those that smoke to those that don't is 1,507/1,615 or 0.9 or (best answer) 9:10.

A triangle's side proportions are 4:6:9, and its perimeter is 190 inches. What are the lengths of its sides?
Answer: 4 + 6 + 9 obviously doesn't equal 190 inches, so look at it like 4x + 6x + 9x = 190. x=10, so the side lengths are 40, 60, and 90.

A triangle's side proportions are 3:2:8 and its perimeter is 72. What are its side lengths?
Answer: 3x + 2x + 8x = 72. 13x = 72, and x = 5.54. So 3(5.54), 2(5.54), and 8(5.54) are the side lengths.

The replica of a statue is 10 inches tall. The real statue is 10 feet tall. What is the ratio of the replica's height to the statue's?
Answer: Convert 10 feet to inches. So 10 in/10 feet = 10 in/120 in. Simplifies to 1/12.

November Something 2013 Math 1050

Padawons. Much to learn there is.


Hk format is just slope intercept format- just danced around.

That's all I have for you today.

11/18/13

Homework: Ch. 4.1 page 181 #21-29 all.

Lots of big things approach, young padawans. On December 19, you have a test! From this point on, each quiz you have could drop the score of a previous, lower quiz score. (Your five highest scores will go on your grade.)

Notes for today:

Triangle classification by angles (see drawing one):
 - If an angle in a triangle is greater than 90 degrees, it's an obtuse triangle.
 - If an angle in a triangle is exactly 90 degrees, it's a right angle triangle, or normal triangle.
 - If all three angles of a triangle are less than 90 degrees, it's an acute triangle.
 Note: α = Alpha, β = Beta, γ = Gamma, δ = Delta

Triangle classification by sides (see drawing two):
 - Equilateral triangles have equal sides and all angles measure 60 degrees.
 - Isosceles triangles have two equal sides and two equal angles.
 - Scalene triangles have no equal sides and no equal angles.
Note: All equilateral triangles are also isosceles triangles, but not all isosceles triangles are equilateral triangles. Like rectangles and squares!

With congruent triangles, all sides and all angles must have the same measure.
With similar triangles, all angles must have the same measure, and the proportions of the sides must be the same.

A dilation makes a shape bigger.
A contraction makes it smaller.

ALL parabolas are similar! Just so you know.

AA (Angle Angle) is not something you can use to prove congruency.

In-class proof (see drawing #3)

math 1050 november 18th 2013

We went over the test today. O_O GOOD JOB YOUNG PADAWONS! Chapter 8 your next test is on monday, the twenty fifth. BUT DON'T CRY BECAUSE YOU GUYS ARE LAZY AND GET THOSE PINK SHEETS THAT GIVE YOU ALL OF THE FREAKING EQUATIONS. =.= and because I, jedi master kristen, am so frustrated- NO NOTES FOR YOU. I HOPE YOU PAID ATTENTION IN CLASS. have a nice day. WITHOUT MY HELPFUL NOTES.