Get reliable answers to your questions at Westonci.ca, where our knowledgeable community is always ready to help. Get detailed and accurate answers to your questions from a dedicated community of experts on our Q&A platform. Join our Q&A platform to connect with experts dedicated to providing accurate answers to your questions in various fields.

Perform the operations:

[tex]\[ 5r - 3s + 8t \][/tex]

What is the magnitude and direction angle of the resultant vector?

A. [tex]\(10.8, \theta=56.3^{\circ}\)[/tex]

B. [tex]\(18.4, \theta=119.4^{\circ}\)[/tex]

C. [tex]\(41.0, \theta=77.3^{\circ}\)[/tex]

D. [tex]\(97.6, \theta=24.2^{\circ}\)[/tex]


Sagot :

Let's analyze the given vector components and calculate their properties. We are given the vector components:

[tex]\[ \mathbf{v} = (r, s, t) = (5, -3, 8) \][/tex]

We'll calculate two main properties: the magnitude of the vector and the direction angle using the components [tex]\( r \)[/tex] and [tex]\( s \)[/tex].

### Step 1: Calculate the Magnitude
The magnitude [tex]\( \|\mathbf{v}\| \)[/tex] of a vector in 3-dimensional space [tex]\(\mathbf{v} = (r, s, t)\)[/tex] is given by the formula:
[tex]\[ \|\mathbf{v}\| = \sqrt{r^2 + s^2 + t^2} \][/tex]
Substituting the given values [tex]\( r = 5 \)[/tex], [tex]\( s = -3 \)[/tex], and [tex]\( t = 8 \)[/tex]:

[tex]\[ \|\mathbf{v}\| = \sqrt{5^2 + (-3)^2 + 8^2} = \sqrt{25 + 9 + 64} = \sqrt{98} \][/tex]

Evaluating [tex]\(\sqrt{98}\)[/tex]:
[tex]\[ \sqrt{98} \approx 9.899 \][/tex]

So, the magnitude of the vector is approximately:
[tex]\[ \|\mathbf{v}\| \approx 9.899 \][/tex]

### Step 2: Calculate the Direction Angle (θ)
The direction angle [tex]\( \theta \)[/tex] in the context of a 3D vector can often be understood as the angle between the projection of the vector on the [tex]\( xy \)[/tex]-plane and the positive [tex]\( x \)[/tex]-axis. This can be calculated as:
[tex]\[ \theta = \arctan\left(\frac{s}{r}\right) \][/tex]

Substituting [tex]\( r = 5 \)[/tex] and [tex]\( s = -3 \)[/tex] into the formula:
[tex]\[ \theta = \arctan\left(\frac{-3}{5}\right) \][/tex]
We convert this angle from radians to degrees:
[tex]\[ \theta \approx -30.964^\circ \][/tex]

So the direction angle is approximately:
[tex]\[ \theta \approx -30.964^\circ \][/tex]

### Consider the Given Options and Find the Closest Match
We compare our calculated magnitude and direction angle to the given options:

1. [tex]\(10.8, \theta = 56.3^\circ\)[/tex]
2. [tex]\(18.4, \theta = 119.4^\circ\)[/tex]
3. [tex]\(41.0, \theta = 77.3^\circ\)[/tex]
4. [tex]\(97.6, \theta = 24.2^\circ\)[/tex]

None of the options match our calculated values ([tex]\(\approx 9.899\)[/tex] for magnitude and [tex]\(-30.964^\circ\)[/tex] for direction). Thus, our result is:

[tex]\[ \rho \approx 9.899, \quad \theta \approx -30.964^\circ \][/tex]
Thanks for using our service. We aim to provide the most accurate answers for all your queries. Visit us again for more insights. We appreciate your visit. Our platform is always here to offer accurate and reliable answers. Return anytime. Get the answers you need at Westonci.ca. Stay informed by returning for our latest expert advice.