3. Slope-Intercept
▰The slope-intercept form of a line is a way of
writing the equation of a line so that the slope of
the line and the y-intercept are easily identifiable.
▰The slope is the steepness of the line, and
the y-intercept is the place the line crosses the y-
axis.
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4. ALGORITHM
▰Step 1: Compute dx = x2 –x1
▰Step 2: Compute dy = y2 –y1
▰Step 3: Compute m = dy / dx
▰Step 4: Compute y = y1 – mx1
▰Step 5: Set (x, y) equal to the lower left-hand end-point and set xend equal to the largest value of x.
If dx < 0, then x = x2, y = y2 and xend = x1.
If dx > 0, then x = x1, y = y1 and xend = x2.
▰Step 6: Test to determine whether the entire line has been drawn. If x>xend, Stop.
▰Step 7: Plot a point at current (x, y) position.
▰Step 8: Increment x: x = x+1.
▰Step 9: Compute the next value of y from the equation y = mx + c.
▰Step 10: Go to Step 6.
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6. Working Process
▰Graph the equation:
▰ y = 2x + 4
▰Before we begin, let's identify the slope and y-
intercept.
▰ Slope = 2 or 2/1
▰ Y-intercept = 4 or (0,4)
▰
▰Step 1: Plot the y-intercept on your graph. The y-
intercept is 4, so I will plot the point (0,4)
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7. Working Process
▰Step 2: From the y-intercept
(0,4) use the slope to plot next
point.
▰ The slope is 2, so we will
rise 2 (up) and run 1 (to the
right).
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8. Working Process
▰Step 3: Draw a line through two points.
▰This line represents the equation y = 2x + 4.
▰Every point on this line is a solution to this
equation.
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9. REAL WORLD EXAMPLE
▰ When climbing stairs or going upslope,
we are experiencing slope intercept.
▰When we’re driving a car upslope too.
▰When we’re trekking up a mountain
too.
▰As well when we’re skiing downslope.
.
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10. ADVANTAGE
▰In this form, one is able to figure the slope of the line by
looking at the coefficient of x.
▰In this form, one is able to figure the x - intercept by
looking at the number next to the slope (if there is one).
And if there isn’t one, then that person already knows the x
and y intercept, as the x intercept and y intercept will be on
the origin (0,0).
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13. HISTORY
. Electroluminescent
displays (ELDs) have a
venerable history starting with
the experiments of Captain
Henry J. Round in 1907
HENRY J. ROUND
EL emission from ZnS phosphor powder
found in 1936 by Destriau (yellow emission)
observation of
electroluminescence from a
solid state diode
14. ELECTROLUMINESCENT DISPLAY (ELD)
▰An electroluminescent display is a category of flat
panel display created by sandwiching a thin film of
electroluminescent material between two plates.
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15. STRUCTURE OF AN ELECTROLUMINESCENT DISPLAY
All Elds Have The Same Basic Structure:
There are at least six layers to the device.
▰ The first layer is a baseplate (usually a rigid insulator like
glass)
▰ The second is a conductor
▰ The third is an insulator
▰ The fourth is a layer of phosphors
▰ The fifth is an insulator
▰ The sixth is another conductor
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16. THIN FLIM ELECTRO-LUMICENT DEVICE
▰All solid state device
▰Electrical breakdown of the phosphor layer for light
generation
▰High brightness
▰Wide viewing angle
▰Red and green lights are bright enough
▰Blue needs more luminance
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18. WORKING PROCESS
▰The thin film EL (Emit Light) glass panel consists of a luminescent
phosphor layer sandwiched between transparent dielectric layers and a
matrix of row and column electrodes.
▰A circuit board containing the drive and control electronics is
connected to the back of the glass panel.
▰Voltage is applied to row and column electrodes causing the area of
intersection (a pixel) to emit light.
▰The result of this solid-state design is a flat, compact, reliable, and
inherently rugged display with exceptionally fast response times (< 1
ms).
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19. ADVANTAGE
▰Low wattage
▰Long life
▰No external circuitry required (no ballast needed to limit current, it can be plugged
directly into AC power and will self-regulate power through it's own resistivity)
▰Can be manufactured into flat flexible panels, narrow strings, and other small shapes
▰Can be made into waterproof computer monitors which are more durable and light
weight than LCDs or Plasma screens.
▰Not directional like LCDs when used as a computer monitor, looks good at all angles
▰EL displays can handle an impressive -60 C to 95 C temperature range, which LCD
monitors cannot do
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20. DISADVANTAGE
▰Not practical for general lighting of large areas due to low lumen output of phosphors (so far)
▰Poor lumens per watt rating, however typically the lamp is not used for high lumen output
anyway
▰Reduced lumen output over time, although newer technologies are better than older phosphors
on this point
▰Flexible flat EL sheets wear out as they get flexed, durability is being worked on
▰The lamps can use significant amount of electricity: 60-600 volts
▰Typical EL Needs a converter when used with DC sources such as on watches (to create
higher frequency AC power, this is audible)
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