Distance Between Two Lines on the Coordinate Plane Distance Formula What is the Distance Formula? The distance formula can be obtained by creating a triangle and finding the length of the hypotenuse. The hypotenuse of the triangle will be the distance between the two points. ex) What is the distance between the points (5, 6) and (– 12, 40) ? Practice Problems 1. Find the distance between the points (20, 16) and (15, 10). click for answer :) 2. Find the distance between the points (55, 40) and (26, 18). click for answer :) 3. Find the distance between the points (-19, -18) and (-29, 21). click for answer :) Web Links http://www.purplemath.com/modules/distform.ht m http://www.teacherschoice.com.au/maths_librar y/analytical%20geometry/alg_15.htm http://www.regentsprep.org/regents/math/geom etry/GCG3/Ldistance.htm Back to problems Back to problems Back to problems Angles Formed with nonparallel lines and a transversal Alexander Shepherd Overview and explanation • 1 3 5 2 4 7 6 Transveral 8 line 2 line 1 Angles adjacent to each other are supplements. • Angles 1 & 7, 2 & 8 are consecutive exterior angles • Angles 3 & 5, 4 & 6 are consecutive interior angles Problems • If angle 1 is a consecutive interior angle to angle 3 which is an alternate interior angle to angle 2, what is angle 2’s supplement? • If angle 4 and interior angle and is a corresponding angle to angle 5 what does it’s alternate exterior equal? Links • http://www.algebralab.org/lessons/lesso n.aspx?file=Geometry_AnglesParallelLi nesTransversals.xml • http://library.thinkquest.org/2609/l2s4.ht m • http://library.thinkquest.org/20991/geo/p arallel.html Today’s Lesson: Simplify Radicals Perfect Squares 4= 2x2 9= 3 x 3 16= 4 x 4 25= 5 x 5 36= 6 x 6 49= 7 x 7 64= 8 x 8 81= 9 x 9 100= 10 x 10 To simplify a radical: You will need to know your perfect squares. This is important for the first step to simplifying radicals. To simplify a radical means to find another expression with the same value It does not mean to find a decimal approximate Steps to Simplifying Radicals • Step 1: Find the largest perfect square which will divide evenly into the number under your radical sign. This means that when you divide, you get no remainders, no decimals, no fractions. • Step 2: Write the number appearing under your radical as the product of the perfect square and your answer from dividing. • Step 3: Give each number in the product its own radical sign. • Step 4: Reduce the "perfect" radical which you have now created. • Step 5: Then you reach your answer Examples 48 16 3 16 3 4 3 3 50 = 3 25 2 3 25 2 = 3 5 2 15 2 18x y z 9 2 x x y z 3x 2 y 2 2xz 5 4 4 4 Extra Help • http://www.themathpage.com/alg/simplifyradicals.htm • http://www.freemathhelp.com/Lessons/Algebr a_1_Simplifying_Radicals_BB.htm • http://www.nutshellmath.com/textbooks_gloss ary_demos/demos_content/alg_simplifying_r adicals.html What is the law of detachment? By, Steven Copertino Law of Detachment • The law of detachment is probably one of the easiest topics in math. • Basically, it states that if p=q is true, then p and q are both true. Still confused? • Here’s some examples… • "If it is sunny outside, I will hang out my washing. " It is sunny outside. Therefore we can say that I will hang out my washing. One more… • “If it snows more than four inches, we will not have school.” We got 2 feet of snow last night. Therefore, we do not have school. • Good Job! Slope Intercept Form •It is probably one of the most frequently used ways to express the equation of a line. •One goal is to be able to find the slope of a line when you are given two coordinates. •We also are trying to find the yintercept. Important Rules • Formula for y intercept: y=mx+b • M is the slope of the line and b is the y- intercept. • When given two points of a line, the first thing you should find is the slope. You would find it using the slope formula. y2 - y1 x2 - x1 • Then once you’ve found m, all you have to do is plug it into the y intercept equation using an x and a y from one of the coordinates that they give you. Example Problems 1. (-2, 8) and (6, 12) 12 -8 6-2 4 12= 1(6)+b b=6 Y= 1x+6 2. (0, 16) and (-8, 22) 22-16 6 -8 - 0 -8 16= 3/-4(0)+b b=16 Y= 3/-4x+16 3. (2, 4) and (1, -2) -2-4 m=6 1-2 4= 6(2)+b b= -8 Y= -8x+b 4 m=1 m= 3/-4 Helpful Sites • http://www.purplemath.com/modules/slopgrph.htm • http://www.purplemath.com/modules/strtlneq.htm • http://www.glencoe.com/sec/math/algebra/algebra1/al gebra1_05/study_guide/pdfs/alg1_pssg_G041.pdf What is logical reasoning? Logical reasoning contains contrapositive, converse, inverse and conditional statements. Conditional and Converse Statement • • • • • The contrapositive and conditional statement both have the same truth value. The conditional is not always true Conditional- If the Jets win this Sunday, then they are going to the super bowl. Converse is- If the Jets are in the super bowl, then they won on Sunday. Converse and inverse have the same truth value. Inverse and Contrapositive Statements • Inverse- make the conditional statement negative Example-If the Jets don’t win on Sunday, then they won’t be in the Super Bowl. • Contrapositive- switch the hypothesis and conclusion and negate both. Example- If there not in the Super Bowl, then Jets didn’t win on Sunday. Helpful Links • http://teacher.scholastic.com/maven/ • http://mathforum.org/pows/library/sets/fu n_logic.html • http://www.iqleap.com/logical-reasoning/ • You could also use your geometry textbook for more practice!