What value of $a$ makes vector ${\bf u} = (a,1)$ perpendicular to ${\bf v} = (3,2)$?

  • 2
    $\begingroup$ Welcome to Mathematics Stack Exchange. Set the dot product $\vec u \cdot \vec v$ to be $0$ $\endgroup$ – J. W. Tanner Nov 24 '19 at 0:32
  • $\begingroup$ Thank you. Alright I got it . $\endgroup$ – aita.kane Nov 24 '19 at 0:37

If $\vec u$ and $\vec v$ are perpendicular, then $\vec u\cdot\vec v=0$.

Thus $(a,1)\cdot(3,2)=3a+2=0$.

Can you take it from here?

  • $\begingroup$ I can now thanks to you. @J. W. Tanner. $\endgroup$ – aita.kane Nov 24 '19 at 0:36

This may help you visualize the problem:

enter image description here

  • $\begingroup$ Thank you @David G. Stork. It helps a lot $\endgroup$ – aita.kane Nov 24 '19 at 1:08

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