Identifying Linear Functions
Using Intercepts
Slope
Slope intercept form
Point Slope form &Slopes of lines
100
What is a function whose graph forms a straight line called?
linear function
100
What is the x-coordinate of the point where the graph intersects the x axis called?
x-intercept
100
What is the slope of a horizontal line?
Zero
100
What is slope intercept form?
y=mx+b
100
Write the linear equation in point slope form: Slope=-7 ; (4,2)
y-2 = -7(x -4)
200
What is the standard form of a linear equation?
Ax+By=C
200
Find the x intercept: 2x- 4y=8
fo x-intercept, y=0 substitute 0 for y: 2x-4(0)=8 solve for x: 2x-0=8 => 2x=8 => x=4 The x-intercept is 4
200
What is the slope of a vertical line?
Undefined
200
Write the equation in slope intercept form: slope=0, y intercept =-5
use y=mx+b y=0x+(-5) y=-5
200
What lines have the same slope?
parallel
300
Tell whether the function is linear and turn it into standard form of linear equation: y=x+3
Yes, linear because it is in slope-intercept form Standard form is -x+y=3 (both x and y must be on the same side of the equation)
300
Find the x and y intercepts of 3x+4y=24
for x-intercept, 3x+4(0)=24 => 3x=24 => x=8 for y-intercept, 3(0)+4y=24 => 4y=24 => y=6
300
Find the slope of (4,-2) and(-1,2)
use slope= rise/run slope = y2-y1 / x2-x1 slope = (2-(-2)) / (-1-4) = -4/5
300
Write the equation in slope intercept form: slope=4 and (2,5) is on the line
begin with point-slope form: y-5=4(x-2) y-5=4x-8 y=4x-3 <- slope intercept form
300
How do you know when you have perpendicular slopes?
When the product of the slopes equal -1 or When slopes are negative reciprocals. Example: 2 (-1/2) = -1
400
Tell whether the set of ordered pairs satisfies a linear function. Explain (2,4), (5,3) (8,2), (11,1)
Yes, constant change in 3 for x. Constant change of -1 in y
400
Find the x and y intercepts of 3x- 2y=12
for x-intercept 3x-2(0)=12 x=4 for y-intercept 3(0)-2y=12 y=-6
400
Find the slope of (20,3000) and (60,2000)
-25
400
Graph the equation: y= 4x-3
y-intercept is -3 rise 4, run 1 begin on (0,-3)
400
Write this equation in point slope form & in slope intercept form: slope=-4, (-1,-2)
Point slope form: y+2= -4(x+1) Slope intercept: y=-4x -6
500
the points (2,3) and (8, 15) are on the same line. write equation of this line in standard form
slope: (15-3) / (8-2)=12/6=2 begin with y-3=2(x-2) => y=2x-1 get both variables on the same side of the equation: y-2x=-1 <- standard form
500
Find the x and y intercepts of 2x + 4y=8. Rewrite equation in the slope-intercept form.
x=4 and y=2 4y=8-2x => y=2-1/2x y=-1/2x+2
500
Find the slope of the line represented by this equation: 6x + 5y=30
6/5
500
Find x- and y-intercepts. What is the meaning of y-intercept? On which axis is the x-intercept? 4x+2y=8
x-int: 4x+2(0)=8 x=2 x-int is on the x-axis y-int: 4(0)+2y=8 y=4 y-intercept shows the "starting point" on the y-axis (Real life connection: for the bank account, if y-intercept is 100 then there was a hundred dollars already in the bank when you start saving same sum every week.)
500
Write the equation in point slope form and in slope intercept form: (1,-4) and (3,2)
Point slope: y-2=3 (x-3) slope intercept: y=3x -7
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