I don't understand the example where you said the root was repeated but the answer came out to two different roots (+/- 12)? Surely the line crosses the x axis at these two points (12,0) and (-12,0). How is that repeated? Please could someone explain.
She isn't working out the root she is working out k which is 'b', she uses the question which says that the root is repeated hence the discriminant (b - 4ac^2) equals 0, to work out k. Also it doesn't matter if k is +12 or -12 because in the equation k (which is b) is being squared and (-12)^2 is the same as (+12)^2 : they both equal 12, so the discriminant will still be 0
'Have fun'
Me : laughs in misery
Sarah you are a star...im studying a level maths and this helps a lot
Fantastic resource for people wanting to learn maths quickly and easily!
Maths is Lovely to hear from you
I don't understand the example where you said the root was repeated but the answer came out to two different roots (+/- 12)? Surely the line crosses the x axis at these two points (12,0) and (-12,0). How is that repeated? Please could someone explain.
She isn't working out the root she is working out k which is 'b', she uses the question which says that the root is repeated hence the discriminant (b - 4ac^2) equals 0, to work out k. Also it doesn't matter if k is +12 or -12 because in the equation k (which is b) is being squared and (-12)^2 is the same as (+12)^2 : they both equal 12, so the discriminant will still be 0
Why can the discriminant be used to work out whether a line intersects a circle or not?
Super.....
Thank uuuu