Question

Find a • b if a = 3i + 8j and b= -0.5i - 4j.

Answer 1

For this case we have the following vectors:
 a = 3i + 8j
 b = -0.5i - 4j
 Using product point we have:
 a.b = (3i + 8j). (- 0.5i - 4j)
 a.b = (3) * (- 0.5) + (8) * (- 4)
 a.b = -1.5 + -32
 a.b = -33.5
 Answer:
 The point product is given by:
 a.b = -33.5
 B. -33.5