Use the dot product to find the magnitude of u if u = 3,–5 .
Use the dot product to find the magnitude of u if u=5i+6j.
+129842 Use the dot product to find the magnitude of u if u = 3,–5
The length of u = √[u2] = √[u (dot) u ] = √[ 3(dot)3 + -5{dot)-5 ] = √[9 + 25] = √34 = about 5.83
Use the dot product to find the magnitude of u if u=5i+6j
Similarly, we have
√[ 5(dot)5 + 6(dot)6] = √ [25 + 36] = √61 = about 7.81
