UNIT 7 - OBJECTIVE 4 - THE STRAIGHT LINE

		There are several formulas for the equation of a line
		1) Point slope of a line
		
		Use this when given slope m and a point on the line.
		Use this when given two points on a line by finding m first.

		2) Slope intercept from a line (y-intercept)
		    y=mx+b
		
		Use this when given slope m and y-intercept
		
		3) General form of a line 
		   Ax+By+C=0 					The graph is always a line.

		4) Special lines
		
		Equation : y=b				
											
		Equation: x=a

		EXAMPLE 1
		Find the slope of the line whose equation is 3x+2y=6

		Solve the equation for y=mx+b because m is the slope.
		

		EXAMPLE 2
		Write the equation of the line through (-2,4) and (-9,2).
		Find the slope 
		
		Use the point slope form of a line (you can use either point)
		

		You can use fraction or avoid fraction.
		     OR			

		These two answers are equivalent

		EXAMPLE 3
		Find the equation of line through (1,-2) and perpendicular to 3x+2y=6

		Find the slope of the given line by solving for y
		2y=-3x+6
		y=-3/2x+3			slope=-3/2

		The slope of the perpendicular to the given line has a slope equal to -(1/(-3/2)) = 2/3
		Now we use point slope formula
		


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