### Home > PC > Chapter 10 > Lesson 10.1.4 > Problem 10-56

10-56.

If two vectors are orthogonal, then their dot product is 0.

**u** · **v** = 3(−16) + (6*a*)(2*a*)

Now set the dot product = 0 and solve for *a*.

10-56.

If two vectors are orthogonal, then their dot product is 0.

**u** · **v** = 3(−16) + (6*a*)(2*a*)

Now set the dot product = 0 and solve for *a*.