Sign in
Please select an account to continue using cracku.in
↓ →
Join Our JEE Preparation Group
Prep with like-minded aspirants; Get access to free daily tests and study material.
Let $$A(2, -3)$$ and $$B(-2, 1)$$ be vertices of a triangle $$ABC$$. If the centroid of this triangle moves on the line $$2x + 3y = 1$$, then the locus of the vertex $$C$$ is the line
Let the coordinates of the third vertex C of the triangle be given by:
$$ (h, k) $$
The coordinates of the given vertices are A(2, -3) and B(-2, 1). Let the coordinates of the centroid of the triangle ABC be denoted as G(X, Y).
The formula for the coordinates of the centroid of a triangle is:
$$ X = \frac{x_1 + x_2 + x_3}{3} $$
$$ Y = \frac{y_1 + y_2 + y_3}{3} $$
Substitute the given values into the centroid formula:
$$ X = \frac{2 + (-2) + h}{3} $$
$$ Y = \frac{-3 + 1 + k}{3} $$
Simplify the numerator expressions for both coordinates:
$$ X = \frac{h}{3} $$
$$ Y = \frac{k - 2}{3} $$
The problem states that the centroid G(X, Y) moves along a specific straight line:
$$ 2x + 3y = 1 $$
Since the point G(X, Y) lies on this line, its coordinates must satisfy the line equation:
$$ 2X + 3Y = 1 $$
Substitute the expressions for X and Y in terms of h and k back into this equation where $$ X = \frac{h}{3} $$ and $$ Y = \frac{k - 2}{3} $$:
$$ 2\left(\frac{h}{3}\right) + 3\left(\frac{k - 2}{3}\right) = 1 $$
Multiply the entire equation by 3 to clear the denominators:
$$ 2h + 3(k - 2) = 3 $$
Expand the terms inside the parentheses:
$$ 2h + 3k - 6 = 3 $$
Isolate the constant terms on the right side of the equation:
$$ 2h + 3k = 3 + 6 $$
$$ 2h + 3k = 9 $$
To find the locus of the moving vertex C, replace the coordinates (h, k) with the general coordinate variables (x, y):
$$ 2x + 3y = 9 $$
Final Answer:
The locus of the vertex C is the line $$ 2x + 3y = 9 $$.
Create a FREE account and get:
Educational materials for JEE preparation