Vector Representation in a Triangle

MathematicsVector GeometryMediumSTEM

Published:

Q.2. In $\triangle PQR$, $\vec{PQ} = 2\vec{a}$, $\vec{QR} = 2\vec{b}$. The midpoint of $\vec{PR}$ is $M$. Find following vectors in terms of $\vec{a}, \vec{b}$. 1) $\vec{PR}$ 2) $\vec{PM}$ 3) $\vec{QM}$

This question includes visual content: A hand-drawn triangle labeled P, Q, R. The side PQ is marked with a vector arrow pointing from P to Q, labeled '2a'. The side QR is marked with a vector arrow pointing from Q to R, labeled '2b'. A line segment connects vertex Q to point M on the side PR. Point M is indicated as the midpoint of PR.

Animated Video Solution

The first half plays free, the full solution is in the app.

Step by Step Written Solution

1
Step 1

Hi Tanishka, let's solve this vector geometry problem step-by-step.

Vector Relations in a Triangle

PQRM2a2b
2
Step 2

We are given that the vector from P to Q is two a, and the vector from Q to R is two b. M is the midpoint of side PR. We want to find vectors PR, PM, and QM in terms of a and b.

3
Step 3

First, let's find the vector P R. By the triangle law of vector addition, the vector from P to R is equal to the sum of the vector from P to Q and the vector from Q to R.

Part 1: Finding Vector PR

$$\vec{PR} = \vec{PQ} + \vec{QR}$$
4
Step 4

Now, we substitute the given vector P Q which is two a, and vector Q R which is two b.

5
Step 5

So we have our first result, vector P R is equal to two a plus two b.

6
Step 6

Next, let's find vector P M. We are given that M is the midpoint of segment P R.

Part 2: Finding Vector PM

Since $M$ is the midpoint of $PR$:

$$\vec{PM} = \frac{1}{2}\vec{PR}$$
7
Step 7

Since vector P M is half of vector P R, we can substitute our previous result for P R into this equation.

8
Step 8

Distributing the factor of one half, we get vector P M equals vector a plus vector b.

The rest of this solution is on Solvi

7 more steps are locked. Watch the full animated, narrated solution for free.

Snap a photo, solve any question like this.

Download on the App Store Get it on Google Play

Free to download · First solutions are on us

100K+Questions solved daily
50K+Students learning
4.8 ★App Store rating

About This Question

Subject
Mathematics
Topic
Vector Geometry
Difficulty
Medium
Exam
STEM
Question Type
Open Ended

Solve any question in seconds

Snap a photo and AI explains it step by step with voice and animation.

Download on the App Store Get it on Google Play
Solvi
The full solution is in the appFree to download · First solutions are on us
Get