## modphysnoob Group Title please look at my drawing @phi @KingGeorge one year ago one year ago

1. modphysnoob Group Title

|dw:1360298829035:dw| find this vector

2. itsmylife Group Title

your x axis coordinate is incorrect

3. itsmylife Group Title

it should be (4,0)

4. modphysnoob Group Title

yes , thanks

That is a beautiful triangle you have there.

6. itsmylife Group Title

then use mid point formula your gonna get, (2,1) as coordinates of bisector n then your vector is , V= 2i +j

7. KingGeorge Group Title

modphys doesn't want the mid point. He want the vector that's perpendicular.

8. itsmylife Group Title

well thats perpendicular bisector that means dividing equally that means mid point

9. KingGeorge Group Title

What I would do, is write the line in the form $$y=-x/2+2$$. The slope of the intersecting line will be $-\frac{1}{-\frac{1}{2}}=2.$ So you have a line that looks like $$y=2x$$ as the line that intersects. Set them equal to each other to get $$2x=-x/2+2\implies 5x/2=2\implies x=1$$.

10. KingGeorge Group Title

Plug that in again, $$x=1\implies y=2(1)=2$$, so the point of intersection is $$(1,2)$$.

11. KingGeorge Group Title

Which in turn means the vector is $\vec{i}+2\vec{j}$

12. modphysnoob Group Title

I got same answer but here what my book did

13. modphysnoob Group Title

14. KingGeorge Group Title

If $$x=.8$$, then the vector is $.8\vec{i}+1.4\vec{j}$ Taking the dot product of that with the vector $4\vec{i}-2\vec{j},$ we get $.8\cdot4-2\cdot1.4=0.4\neq0$so that solution is wrong.