F flowerp Active Member Joined May 15, 2017 Messages 124 Gender Undisclosed HSC N/A Jul 13, 2018 #1 Hi every1, I need help with the following question please: If points (-3k,1), (k-1,k-3) and (k-4,k-5) are collinear, find the value of k. Thanks !!
Hi every1, I need help with the following question please: If points (-3k,1), (k-1,k-3) and (k-4,k-5) are collinear, find the value of k. Thanks !!
B boredofstudiesuser1 Active Member Joined Aug 1, 2016 Messages 570 Gender Undisclosed HSC 2018 Jul 13, 2018 #2 flowerp said: Hi every1, I need help with the following question please: If points (-3k,1), (k-1,k-3) and (k-4,k-5) are collinear, find the value of k. Thanks !! Click to expand... If they're collinear, each segment is going to have the same gradient. (use gradient formula) m=(y2-y1)/(x2-x1) A(-3k,1) B(k-1,k-3) C(k-4,k-5) m of AB: (k-3-1)/(k-1-(-3k)) = (k-4)/(4k-1) m of BC: (k-5-(k-3))/(k-4-(k-1)) = -2/-3 = 2/3 so we know 2/3 = (k-4)(4k-1) 8k-2 = 3k-12 5k = -10 k=-2 Hopefully that's the right answer.
flowerp said: Hi every1, I need help with the following question please: If points (-3k,1), (k-1,k-3) and (k-4,k-5) are collinear, find the value of k. Thanks !! Click to expand... If they're collinear, each segment is going to have the same gradient. (use gradient formula) m=(y2-y1)/(x2-x1) A(-3k,1) B(k-1,k-3) C(k-4,k-5) m of AB: (k-3-1)/(k-1-(-3k)) = (k-4)/(4k-1) m of BC: (k-5-(k-3))/(k-4-(k-1)) = -2/-3 = 2/3 so we know 2/3 = (k-4)(4k-1) 8k-2 = 3k-12 5k = -10 k=-2 Hopefully that's the right answer.
