मराठी

O is the origin and A is (a, b, c). Find the direction cosines of the line OA and the equation of plane through A at right angle to OA.

Advertisements
Advertisements

प्रश्न

O is the origin and A is (a, b, c). Find the direction cosines of the line OA and the equation of plane through A at right angle to OA.

बेरीज
Advertisements

उत्तर

Given, O(0, 0, 0) and A(a, b, c)

So, the direction ratios of OA = a – 0, b – 0, c – 0 = a, b, c

And, the direction cosines of line OA

`(a/(sqrt(a^2 + b^2 + c^2)), b/sqrt(a^2 + b^2 + c^2), c/sqrt(a^2 + b^2 + c^2))`

Now, the direction ratios of the normal to the plane are (a, b, c).

We know that, the equation of the plan passing through the point A(a, b, c) is

a(x – a) + b(y – b) + c(z – c) = 0

ax – a2 + by – b2 + cz – c2 = 0

ax + by + cz = a2 + b2 + c2

Thus, the required equation of the plane is ax + by + cz = a2 + b2 + c2 

shaalaa.com
  या प्रश्नात किंवा उत्तरात काही त्रुटी आहे का?
पाठ 12: Introduction to Three Dimensional Geometry - Exercise [पृष्ठ २३६]

APPEARS IN

एनसीईआरटी एक्झांप्लर Mathematics Exemplar [English] Class 11
पाठ 12 Introduction to Three Dimensional Geometry
Exercise | Q 14 | पृष्ठ २३६

व्हिडिओ ट्यूटोरियलVIEW ALL [1]

संबंधित प्रश्‍न

The x-axis and y-axis taken together determine a plane known as_______.


Coordinate planes divide the space into ______ octants.


Name the octants in which the following points lie: 

 (7, 4, –3)


Find the image  of: 

 (–5, 0, 3) in the xz-plane. 


Planes are drawn through the points (5, 0, 2) and (3, –2, 5) parallel to the coordinate planes. Find the lengths of the edges of the rectangular parallelepiped so formed. 


Find the distances of the point P(–4, 3, 5) from the coordinate axes. 


Determine the points in zx-plane are equidistant from the points A(1, –1, 0), B(2, 1, 2) and C(3, 2, –1). 


Find the point on y-axis which is equidistant from the points (3, 1, 2) and (5, 5, 2).


Prove that the triangle formed by joining the three points whose coordinates are (1, 2, 3), (2, 3, 1) and (3, 1, 2) is an equilateral triangle.


Find the coordinates of the point which is equidistant  from the four points O(0, 0, 0), A(2, 0, 0), B(0, 3, 0) and C(0, 0, 8).


If A(–2, 2, 3) and B(13, –3, 13) are two points.
Find the locus of a point P which moves in such a way the 3PA = 2PB.


Verify the following: 

(0, 7, 10), (–1, 6, 6) and (–4, 9, –6) are vertices of a right-angled triangle.


Find the locus of the point, the sum of whose distances from the points A(4, 0, 0) and B(–4, 0, 0) is equal to 10.


Show that the points A(1, 2, 3), B(–1, –2, –1), C(2, 3, 2) and D(4, 7, 6) are the vertices of a parallelogram ABCD, but not a rectangle.


What is the locus of a point for which y = 0, z = 0?


Find the point on y-axis which is at a distance of  \[\sqrt{10}\] units from the point (1, 2, 3).


Let (3, 4, –1) and (–1, 2, 3) be the end points of a diameter of a sphere. Then, the radius of the sphere is equal to 


XOZ-plane divides the join of (2, 3, 1) and (6, 7, 1) in the ratio


What is the locus of a point for which y = 0, z = 0?


The coordinates of the foot of the perpendicular from a point P(6,7, 8) on x - axis are 


The perpendicular distance of the point P (6, 7, 8) from xy - plane is


A plane meets the co-ordinates axis in A, B, C such that the centroid of the ∆ABC is the point (α, β, γ). Show that the equation of the plane is `x/alpha + y/beta + z/γ` = 3


Find the co-ordinates of the foot of perpendicular drawn from the point A(1, 8, 4) to the line joining the points B(0, –1, 3) and C(2, –3, –1).


If α, β, γ are the angles that a line makes with the positive direction of x, y, z axis, respectively, then the direction cosines of the line are ______.


If a line makes angles `pi/2, 3/4 pi` and `pi/4` with x, y, z axis, respectively, then its direction cosines are ______.


If a line makes an angle of `pi/4` with each of y and z axis, then the angle which it makes with x-axis is ______.


Find the equation of the plane through the points (2, 1, 0), (3, –2, –2) and (3, 1, 7).


Find the angle between the lines whose direction cosines are given by the equations l + m + n = 0, l2 + m2 – n2 = 0


If a variable line in two adjacent positions has direction cosines l, m, n and l + δl, m + δm, n + δn, show that the small angle δθ between the two positions is given by δθ2 = δl2 + δm2 + δn2


Two systems of rectangular axis have the same origin. If a plane cuts them at distances a, b, c and a′, b′, c′, respectively, from the origin, prove that

`1/a^2 + 1/b^2 + 1/c^2 = 1/(a"'"^2) + 1/(b"'"^2) + 1/(c"'"^2)`


Find the foot of perpendicular from the point (2,3,–8) to the line `(4 - x)/2 = y/6 = (1 - z)/3`. Also, find the perpendicular distance from the given point to the line.


Find the equations of the line passing through the point (3,0,1) and parallel to the planes x + 2y = 0 and 3y – z = 0.


Show that the straight lines whose direction cosines are given by 2l + 2m – n = 0 and mn + nl + lm = 0 are at right angles.


If l1, m1, n1 ; l2, m2, n2 ; l3, m3, n3 are the direction cosines of three mutually perpendicular lines, prove that the line whose direction cosines are proportional to l1 + l2 + l3, m1 + m2 + m3, n1 + n2 + n3 makes equal angles with them.


The sine of the angle between the straight line `(x - 2)/3 = (y - 3)/4 = (z - 4)/5` and the plane 2x – 2y + z = 5 is ______.


The plane 2x – 3y + 6z – 11 = 0 makes an angle sin–1(α) with x-axis. The value of α is equal to ______.


The angle between the planes `vecr.(2hati - 3hatj + hatk)` = 1 and `vecr.(hati - hatj)` = 4 is `cos^-1((-5)/sqrt(58))`.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×