Watch Video on Slope Intercept Form – Algebra Help
Saturday, February 27th, 2010
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/slopeinterceptform.php Students learn to use slope-intercept form to graph a line. Slope-intercept form is y = mx + b form, where m represents the slope, and b represents the y-intercept. So if the equation of a line is y = 3/4 x — 2, then the line is written in y = mx + b form, with m = 3/4 and b = -2. To graph the line, start with the y-intercept, or b, of –2. From there, take the slope, or m, of 3/4, plot a second point, and graph the line.
Duration : 0:2:4
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/interceptmethod.php Students learn to graph a given linear equation using the intercept method. The x-intercept is the point on the graph where the line crosses the x-axis, so the x-intercept will always have a y-coordinate of 0, and the y-intercept is the point on the graph where the line crosses the y-axis, so the y-intercept will always have an x-coordinate of 0. So to graph x + 2y = 6 using the intercept method, substitute a 0 in for y to find the x-intercept, to get x + 2(0) = 6, or x = 6. So the x-intercept is (6, 0). And substitute a 0 in for x to find the y-intercept, to get (0) + 2x = 6, or x = 3. So the y-intercept is (0, 3). Next, plot the intercepts, (6, 0) and (0, 3), and connect these points with a line.
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/graphingsystemsofequations.php Students learn to solve a system of linear equations by graphing. The first step is to graph each of the given equations, then find the point of intersection of the two lines, which is the solution to the system of equations. If the two lines are parallel, then the solution to the system is the null set. If the two given equations represent the same line, then the solution to the system is the equation of that line. Visit http://www.yourteacher.com to browse our huge library of online math videos and try a free online lesson!
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/graphingquadraticfunctions.php Students are introduced to the parent graph for quadratic functions: y = x^2. Students then learn how to graph quadratic functions, such as y = x^2 + 2, and how to identify the vertex, minimum, x- and y-intercepts, axis of symmetry, one pair of symmetric points, and the domain and range of the graph. Finally, students are asked to compare their graph with the parent graph for quadratic functions.
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/solvinginequalities.php Students learn that when solving an inequality, such as –3x is less than 12, the goal is the same as when solving an equation: to get the variable by itself on one side. Note that when multiplying or dividing both sides of an inequality by a negative number, the direction of the inequality sign must be switched. For example, to solve –3x is less than 12, divide both sides by –3, to get x is greater than -4. And when graphing an inequality on a number line, less than or greater than means an open dot, and less than or equal to or greater than or equal to means a closed dot.
Access full lesson containing this video at: http://www.yourteacher.com/algebra1/graphinglinearinequalities.php Students learn to graph inequalities in two variables. For example, to graph y is less than x + 2, the first step is to graph the boundary line y = x + 2, using the chart method from lesson 4B. Note that greater than or less than means that the boundary line will be dotted, and greater than or equal to or less than or equal to means that the boundary line will be solid. To determine which side of the boundary line to shade, substitute a test point, such as (0, 0), into the original inequality, y is less than x + 2. Since (0) is less than (0) + 2, or 0 is less than 2, is a true statement, the side of the line that contains the point (0, 0) is shaded.