1. ## Vectors question

I can't finish this attached vectors question.

2. Originally Posted by Stuck Man
I can't finish this attached vectors question.
Dear Stuck Man,

There is a calculation error in your result for $\overline{PQ}$. It must be, $\overline{PQ}=\frac{1}{2}\underline{b}-\frac{3}{10}\underline{a}$.

After you correct this you can equate the two results you obtained for $\overline{QR}$. Then considering the coefficients of $\underline{a}~and~\underline{b}$ you can find k and n.

3. I thought that might be wrong earlier. I still don't know how to find n and k.

4. Originally Posted by Stuck Man
I thought that might be wrong earlier. I still don't know how to find n and k.
Dear Stuck Man,

$\overline{QR}=\frac{n}{10}(5\underline{b}-3\underline{a})=\frac{1}{2}(1+2k)\underline{b}-\frac{1}{2}\underline{a}$

Now, you can equate the coefficients of $\underline{a}~and~\underline{b}$.

5. I have done it now. My mistake earlier did not help. I originally made an equation from the two expressions fo r the vector QR. Thanks.