Question
Question: In what ratio does the point \[\left( {\dfrac{{24}}{{11}},y} \right)\], divide the line segment join...
In what ratio does the point (1124,y), divide the line segment joining the points P(2,−2) & Q(3,7)? Also find the value of y?
Solution
In this question, we have to find out the ratio when we divide a line segment by the given point.
First we put the given points p and Q in the section formula and equate it with the coordinates of the given point then we will get the ratio and the value of y.
Formula used: Section formula:
The coordinate of P(x, y) which divides the line segment joining the points A (x1,y1) and B (x2,y2) internally in the ratio m:n are
(m+nmx2+nx1,m+nmy2+ny1)
Complete step-by-step answer:
It is given that, the point(1124,y), divide the line segment joining the points P(2,−2) & Q(3,7).
Let, the point (1124,y), divide the line segment joining the points P(2,−2)& Q(3,7)in the ratio m:n.
Then applying section formula we get, the coordinate of (x, y) which divides the line segment joining the points P(2,−2)& Q(3,7)internally in the ratio m:n are
(m+nm×3+n×2,m+nm×7+n×−2)
Here (x,y) is given by (1124,y) .
Equating the x coordinates we get,
\Rightarrow$$$\dfrac{{m \times 3 + n \times 2}}{{m + n}} = \dfrac{{24}}{{11}}$$
Let us multiply the numerator term and we get,
\Rightarrow\dfrac{{3m + 2n}}{{m + n}} = \dfrac{{24}}{{11}}$$
Now we have to take cross multiplication and we get
$\Rightarrow33m + 22n = 24m + 24n
Let us take same as one side and we get,
$\Rightarrow$$$33m - 24m = 24n - 22n
On subtracting we get,
\Rightarrow$$$9m = 2n$$
Let us divided the term
Then,$$\dfrac{m}{n} = \dfrac{2}{9}$$
Also, equating the y coordinate we get,
\Rightarrow$$\dfrac{{m \times 7 + n \times - 2}}{{m + n}} = y$$
On multiplying the term and we get \Rightarrow\dfrac{{7m - 2n}}{{m + n}} = y$$
Dividing numerator and denominator of left hand side by n,
$\Rightarrow\dfrac{{\dfrac{{7m - 2n}}{n}}}{{\dfrac{{m + n}}{n}}} = y
Let us rewrite it as,
$\Rightarrow$$$\dfrac{{7\dfrac{m}{n} - 2\dfrac{n}{n}}}{{\dfrac{m}{n} + \dfrac{n}{n}}} = y
Putting the value of nm and we get
\Rightarrow$$$\dfrac{{7 \times \dfrac{2}{9} - 2}}{{\dfrac{2}{9} + 1}} = y$$
On multiplying and take the LCM of numerator and denominator we get,
\Rightarrowy = \dfrac{{\dfrac{{14 - 18}}{9}}}{{\dfrac{{2 + 9}}{9}}}$$
On adding we get
$\Rightarrowy = \dfrac{{\dfrac{{ - 4}}{9}}}{{\dfrac{{11}}{9}}}
On cancel the denominator term and we get
$\Rightarrow$$$y = \dfrac{{ - 4}}{{11}}
Thus we get, m:n=2:9 and y=11−4.
The point (1124,y), divide the line segment joining the points P(2,−2) & Q(3,7) in 2:9 Also the value of y is 11−4.
Note: In geometry, The section formula tells us the coordinates of the point which divides a given line segment into two parts such that their lengths are in the ratio m:n.
The coordinate of P(x,y) which divides the line segment joining the points A (x1,y1) and B (x2,y2) internally in the ratio m:n are
(m+nmx2+nx1,m+nmy2+ny1).