We read your photo as:

Given: A = 3i + 4j + 2k, B = 2i − j + 5k. Calculate A - B and A x B

Mathematics

ScanSolve AI Answer

Answer

A⋅B=12A \cdot B = 12

A×B=22i−11j−11kA \times B = 22i - 11j - 11k

Step-by-step solution

2 steps

Given the vectors:
A=3i+4j+2kA = 3i + 4j + 2k
B=2i−j+5kB = 2i - j + 5k

  1. Calculate the dot product A⋅BA \cdot B.

    The dot product is calculated by multiplying corresponding components and summing the results.

    A⋅B=(3)(2)+(4)(−1)+(2)(5)A \cdot B = (3)(2) + (4)(-1) + (2)(5) A⋅B=6−4+10A \cdot B = 6 - 4 + 10 A⋅B=2+10A \cdot B = 2 + 10 A⋅B=12A \cdot B = \boxed{12}
  2. Calculate the cross product A×BA \times B.

    The cross product can be calculated using the determinant of a matrix:

    A×B=∣ijk3422−15∣A \times B = \begin{vmatrix} i & j & k \\ 3 & 4 & 2 \\ 2 & -1 & 5 \end{vmatrix} A×B=i((4)(5)−(2)(−1))−j((3)(5)−(2)(2))+k((3)(−1)−(4)(2))A \times B = i((4)(5) - (2)(-1)) - j((3)(5) - (2)(2)) + k((3)(-1) - (4)(2)) A×B=i(20−(−2))−j(15−4)+k(−3−8)A \times B = i(20 - (-2)) - j(15 - 4) + k(-3 - 8) A×B=i(20+2)−j(11)+k(−11)A \times B = i(20 + 2) - j(11) + k(-11) A×B=22i−11j−11kA \times B = \boxed{22i - 11j - 11k}
Was this helpful?

Still stuck on this one?

Ask a follow-up, and the answer starts from this question.

Got a different question?Ask your own question
Handwritten step-by-step solution preview

Handwritten Step-by-Step Solution

Get this as a handwritten image on WhatsApp — like a tutor wrote it for you.

Try on WhatsApp