Homework LogWed

10/28

Lesson 3 – 1

Learning Objective: To graph linear equations & find slope

Hw: #301 Pg. 168 #1 – 29 odd

10/28/15 Lesson 3 – 1 Linear Equations Day 1

Advanced Math/Trig

Ch 3 TEST onMonday 11/16/15

Ch 3 Quiz onThursday 11/12/15

Learning Objective

To graph linear equations

To find x & y intercepts

To find slope

To find midpoint

Linear Equation: Ax + By = C

Graph by finding: x – intercept y -

intercept(x , 0) (0 , y)let y = 0 let x = 0Solve for x Solve for y

Slope Intercept Form: y = mx + b

Graph y-int (0, b)Use slope (m) to find another point

1. 2x + 3y = 6 Let x=0: 2(0) +3y = 6

3y = 6 y = 2

(0, 2)

Let y=0: 2x +3(0) = 6

2x = 6

x = 3

(3, 0)

X-int

Y-int

Graph intercepts and connect the dots

Graph & Find x & y intercepts

y

x

(0, 2)

(3, 0)

y

x

Graph & Find x & y intercepts

(0, 2)

(2, –3)

y-int

Find x-int: Let y = 0 0 = (2) 0 =( )(2)0 = –5x + 45x = 4x = (, 0)

y = mx + b

b = 2 (0, 2)

𝑚=−52

or 2.

3. Graph 3y = – 6x

x & y intercept both at (0, 0)

Get into y = mx + b

3y = – 6x

y = – 2x

m = y – int (0, 0)

Graph & Find x & y intercepts

y

x

Two Special Cases

x = -3 (no y)

y = 2 (no x)I only see an

“x” It

goes thru

x-axis

I only see a “y”

It goes thru y-

axis

y

x

Vertical line thru (-3, 0)

Undefined Slope

Horizontal line thru

(0, 2)Zero Slope

ZeroUndefined

4. Graph 3x = 12It ONLY has x, so

solve for x.

3x = 12x = 4

x ALWAYS equals 4

Graphing vertical lines

5. Graph a line with slope of 0 and goes through (-3, 4)

Slope = 0

Horizontal Line

at y = 4

Slope Formula

Given 2 points: (x1, y1) and (x2, y2)

The slope of the line through the points is

𝑆𝑙𝑜𝑝𝑒=𝑚= 𝑟𝑖𝑠𝑒𝑟𝑢𝑛

=𝑦2− 𝑦1

𝑥2− 𝑥1

6. Find slope (3, -5) (7, -2)

(x1, y1) (x2, y2)

Find Slope

Special Cases = 0

= undefined

way!

7. (3, 1) & (– 4, 1)

horizontal line!

At y = 1

Find Slope

8. (7, 3) & (7, 1)

vertical line!

at x = 7

Find Slope

CANNOT DIVIDE BY ZERO!!

Midpoint Formula

1 1 2 2

1 2 1 2

Given ( , ) , ( , )

Find the midpoint

,2 2

x y x y

x x y y

Find Midpoint9. (4, 0) & (– 10, 3)

(x1, y1) (x2, y2)

Midpoint =

=

=

Find Midpoint10. (a, b) & (– a, b)

(x1, y1) (x2, y2)

Midpoint =

=

=

=

Find Midpoint11. (, 0) & (, 0)

(x1, y1) (x2, y2)

Midpoint =

=

=

=

=

=

=

=

Ticket Out the Door

None today!

Homework

#301 Pg. 168 #1 – 29 odd