Online Course Discussion Forum

Math Challenge IIA Algebra

 
 
ZhangYizhou的头像
Math Challenge IIA Algebra
ZhangYizhou - 2019年08月18日 Sunday 11:45
 
3.18 Quick Response Question


Can you tell me why the online answer says -2 divided by 1/2=4?

Is it suppose to be -4?

 
ReynosoDavid的头像
Re: Math Challenge IIA Algebra
ReynosoDavid - 2019年08月19日 Monday 15:04
 

This seems to be a typo, since the sum of the roots $r + s = 2$. So, the solution should say $$\dfrac{1}{r} + \dfrac{1}{s} = \dfrac{r + s}{rs} = \dfrac{2}{\frac{1}{2}} = 4.$$

Thanks for pointing this out!