I was wondering how would you directly sketch a line which is in the form ax + by + c = 0. Like for example. how would you sketch 2x + 3y + 5 = 0 without rearranging for y or something. Thanks for the video btw.
Good question, and sorry for the delay in replying! Without rearranging, my approach would be to set x=0, which quickly shows that y=-5/3, meaning the line passes (0, -5/3). I would then set y=0, which gives x=-5/2, meaning the line passes (-5/2, 0). Knowing two coordinates is enough to sketch the line!
I was wondering how would you directly sketch a line which is in the form ax + by + c = 0. Like for example. how would you sketch 2x + 3y + 5 = 0 without rearranging for y or something. Thanks for the video btw.
Good question, and sorry for the delay in replying! Without rearranging, my approach would be to set x=0, which quickly shows that y=-5/3, meaning the line passes (0, -5/3). I would then set y=0, which gives x=-5/2, meaning the line passes (-5/2, 0). Knowing two coordinates is enough to sketch the line!
Ok thanks @@BicenMaths
do they disallow y=mx+c at A-level or something? or is it going to be useful later in the course so you're making it easier for your students?
It’s allowed! It’s just the new formula is far quicker and more useful for questions later on in the course!