Trigonometry Study Guide? Help please?

Question

5.
sketch the vector as a position vector and find its magnitude
v=3i-4j

6. Find the specified vector or scalar
u= -3i-6j, v=6i+8j; find u+v

Answer 1

5) Let the vector be v = 3i - 4j

     The vector diagram can be displayed as follows:

 

Magnitude of the vector = |v| =√(3^2 + 4^2)

                                                  = √(9 + 16)

                                                  = √25

                                                  =5

Therefore magnitude of the vector is 5

Answer 2

6)  Given that,

                                u= -3i-6j and v=6i+8j

               u + v  = (3i - 6j) + (6i + 8j)

                         = 3i - 6j + 6i + 8j

                         = 3i + 2j

              Therefore u+v = 3i+2j.