Question

Given that
A=3i−2j-k
,
B=2i−4j−3k
and
C=−i+2j+2k
. Find 2A-3B-5C

(√30)

(√15)

(√11)

(√5)

Answer 1

Answer on Question #56009 – Math - Vector Calculus

Given that

A=3i-2j+k,

B=2i-4j-3k

and

C=-i+2j+2k.

Find 2A-3B-5C

(√30)

(√15)

(√11)

(√5)

Solution

$$\begin{array}{l} 2 \overline{A} - 3 \overline{B} - 5 \overline{C} = \\ = (2 \times 3 - 3 \times 2 - 5 \times (-1))i + (2 \times (-2) - 3 \times (-4) - 5 \times 2)j + (2 \times 1 - 3 \times (-3) - 5 \times 2)k = \\ = 5i - 2j + 1k \\ \end{array}$$ $$\left| 2 \overline{A} - 3 \overline{B} - 5 \overline{C} \right| = \sqrt{5^2 + (-2)^2 + 1^2} = \sqrt{25 + 4 + 1} = \sqrt{30}$$

Answer: √30.

www.AssignmentExpert.com