Slope of a Straight Line ميل الخط المستقيم – Math Grade 8 ماث ثانية إعدادي

Hello my students, how are you? Today we'll explain from master book lesson number eight the last lesson geometric about slope of the straight line. We can find the slope by write the difference between y2 and y1 over x2 and x1. Look at with me then the measure of the steepness of the line like this straight line It's the ratio between the vertical change of and the horizontal change of x-axis. We can find the slope y2 - y1 / x2 - x1. We call it the range like this point. We can find the slope right 3 - - 2. No in this correct it must start from Solution will be 4 4 - 1 over 3 - - 2. The last solution is correct. Okay. The slope will be undefined if straight line par to yaxis. Slope will be equal line to will be negative. The straight line cut xaxis at the point and angle will be this line. straight line affect x-axis at point and it will be accurate then the slope will be positive this question we can find the slope by this method and this question also by using first we want to find the slope of eB look at here al found the order of point was -2 and one and point was 2 and 4 in the slope of EB equal 1 4 - 1 / 2 - - 2 it will be 2 + 2 4 - 1 = 3 2 + 2 4 the result will be / 4 and we want to find the slope of the order of point look at here was 2 and one in the slope to BD it will be undefined because it's paral to Y-axis it will be undefined why undefined because the straight line BD parallel to Y-axis and slope of number three of EC will be equal slope of AC will be equal because it's paralle axis and slope of PC slope of PC. We have point DT and one and 4 and one. The order of point is 4 and 1. Then the slope of We have and was 2 and 4 and 4 and 1. We can write 1 - 4. 1 - 4 over 4 - 2. 1 - 4 is -3 and 4 - 2 = 2 then the slope will be -3 / 2 is the slope of PC BC negative because the straight line here decreased. Now we will solve the equation to find the unknown this question try to solve. Find the slope of each of straight line and Okay, we can find the slope about straight line by put the order of any two points. Choose any two points pointing to the straight line Look at here the point will be 0 and zero pointing to And also we have point like -2 and 2 -2 and 2 also pointing to straight line Then we can find the slope. Write 2 - 0 over -2 - 0. 2 - 0 is 2 and -2 - 0 is -2. The result will be -1. The slope of straight line And choose two binds pointing to like this point is -2 and zero pointing to And also show the point like this two and two. spoiling to straight line in. Then we find slope 2. We have two points 2 - 0 over 2 - - 2. It will be 2 + 2. 2 - 0 is 2 and 2 + 2 4 2 over 4 it will be 1 / 2. And the slope of straight line passing through two points. Our straight line of straight line and it will be half. Okay. You must choose to point which poling to or satisfy the straight line. Next question. Prove that the points are colinear by using the slope. We can prove that by find the slope of AB. This question number one. We found the slope of AB. we can write - 1 - 0 1 - 0 first up over 3 - 6. 1 - 0 it will be 1 and 3 - 6 is -3. The result will be 1 / 3. And slope of BC and we can write -2 - -1 it will be -2 + 1 / 0 - 3 -2 + 1 will be 1 /3 the result will be 1 / 3 they are equivalent such that is falling into straight line here AB and BC and such that m1 equal to m_sub_2 and bing to zen the slope equivalent meaning and and are colar and are colar they are colar Okay, understood. Number two, prove that points in our vertices of triangle. We can prove that vertices triangle by right three slopes not have the same result because and or if we prove that not colinar it's meaning it will be our vert of triangle then we can find slope of and here we can write 2 minus 1 and 1 - - 2 1 + 2 2 - 1 = 1 1 + 2 = 3 slope here we can write 2 - 1 / 1 - - 2 the slope of ML we have ML right -2 - 2 over 3 - 1 -2 - 2 is4 and - 1= 24 / 2 is -2 and slope of and we can write -2 - 1 over 3 - - 2 3 + 2 we have -2 - 1 3 and 3 + 2 5 then slope 1 not equal slope 2 not equal Slope three then the three points not colar then three point and are not colar they are not colinear okay not colar it's meaning they are vertices of triangle next question. Try to solve number five. Give me MB and slope of EB equalative 1. We know slope of AB equal we can write the slope equal Y2 - Y1 over X2 - X1. Slope right here. - 2 it will be + 2 over 0 - 3 the slope here will be equal -1 then + 2 over3 is -1 *3 = 3 then + 2 = 3 the value of it will be 1 next number two we have points and lying on the same line means The slope one equal slope two. And the slope of AB equal slope of BC is your equivalent EB look at here and right 2 - 3 over 4 - 2 equal slope of BC and write minus 2 over 8 - 4 right - 2 / 4 = 2 - 3 - 1 / 4 - 2 = 2. Then - 2 = here 4 *1 / 2 it will be4 / 2 it will be -2. So - 2 will be equal -2 the value of will be zero. Okay. Next function you can combining between two speed about one and two there's difference between D2 and D1 and T2 and T1 we can find the velocity okay speed between ais we can divide it by distance by we give velocity height horizontal divide horizontal Since we can find the slope about the root okay with the curve of the root like this the question we can comparing between slope one and slope two find the curve root of rate of 3 for every 36 horizontal the slope We can write stop one equal vertical over horizontal. The traces at of rate 3 of every 36 horizontal. We have vertical and horizontal 3 per 36 Then the slope here 1 / 12. Slope one. And slope two. What is the height of the end road? The length of the root 900 Okay, we want to find if the horizontal or the len was 900. This is the lens and down the horizontal meters. He give me raises at rate of 3 for every 36 horizontal meter. What is the height at the end of the road if the length of the road is 900 the 0900 down. Okay. What we can find the height here? What is the height of the end? Understood? We can write slope one equal slope 2 is constant. Then 3 over 36. We can write this 3 over 36= over 900. Then will be equal 3 product by 900 over 36. 3 * 900 / 36 then the distance will be 75. Okay, the length will be 75 of the height. If the horizontal will be 900 then the height will be 75 We can find the slope also from graphically about this table. We can find the slope by put two points. You want to find slope. Choose two points and We have here the distance and the time. We know the velocity equals distance divided by time. He give me the table from 0 to 10. time here from 0 to 10 and 1 to 20 and 2 to 30 like this you want to find the speed we can write the slope we have two points 0 and 10 and the other point we have 1 and 20 you can write 20 - 10 over 1 - 0 20 - 10 is 10 over 1 the result will be 10 the velocity will 10 10 distance here by kilometer bears the time in hours there the velocity will be 10 kilome per 1