Answered

Let u=(5,-12) and c=-3 what is || cu || ?A.-39 B.21 C.39 D.51 i need help badly

Verified Answer :

lukyo

If you're using the app, try seeing this answer through your browser:  https://brainly.com/question/3184618

——————————

\(\mathsf{c}\cdot \overrightarrow{\mathsf{u}}=\mathsf{-\,3\cdot (5,\,-12)}\)


Therefore,

\(\left\|\mathsf{c}\cdot \overrightarrow{\mathsf{u}}\right\|=\mathsf{\left\|-\,3\cdot (5,\,-12)\right\|}\\\\ \left\|\mathsf{c}\cdot \overrightarrow{\mathsf{u}}\right\|=\mathsf{\left|-\,3\right|\cdot \left\|(5,\,-12)\right\|}\\\\ \left\|\mathsf{c}\cdot \overrightarrow{\mathsf{u}}\right\|=\mathsf{3\cdot \sqrt{5^2+(-12)^2}}\)

\(\left\|\mathsf{c}\cdot \overrightarrow{\mathsf{u}}\right\|=\mathsf{3\cdot \sqrt{25+144}}\\\\ \left\|\mathsf{c}\cdot \overrightarrow{\mathsf{u}}\right\|=\mathsf{3\cdot \sqrt{169}}\\\\ \left\|\mathsf{c}\cdot \overrightarrow{\mathsf{u}}\right\|=\mathsf{3\cdot \sqrt{13^2}}\\\\ \left\|\mathsf{c}\cdot \overrightarrow{\mathsf{u}}\right\|=\mathsf{3\cdot 13}\)

\(\left\|\mathsf{c}\cdot \overrightarrow{\mathsf{u}}\right\|=\mathsf{39}\quad\longleftarrow\quad\textsf{this is the answer (option C. 39)}\)


I hope this helps. =)

The value of \(||c.\overrightarrow {u}||\) is  39 and this can be determined by using the property of dot product and formula to find the vector magnitude.

Given :

  • u = (5,-12)
  • c = -3

To determine the value of \(||c.\overrightarrow {u}||\), calculations is as follows:

\(||c.\overrightarrow {u}||\) = \(||-3.(5,-12)||\)

\(||c.\overrightarrow{u}|| = |-3|.||(5,-12)||\)

\(||c.\overrightarrow{u}|| = |-3|.\sqrt{(5)^2+(-12)^2}\)

\(||c.\overrightarrow{u}|| = 3.\sqrt{25+144}\)

\(||c.\overrightarrow{u}|| = 3.\sqrt{169} = 3\times 13\)

\(||c.\overrightarrow{u}|| = 39\)

Therefore, the correct option is C).

For more information, refer to the link given below:

https://brainly.com/question/9523059

Related Questions