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/geometry/tangentline.php Students learn the following theorems related to tangents. If a line is tangent to a circle, then the line is perpendicular to the radius at the point of tangency. If a line is perpendicular to a radius at its outer endpoint, then the line is tangent to the circle. If two tangent segments are drawn to a circle from an external point, then the tangent segments are congruent. Students are then asked to use these theorems to find missing segment lengths and missing angle measures in given figures. Students also learn the definitions of common internal tangents and common external tangents.