Solution: It is given that a cube with 2 units edge, one of whose vertices coincides with the origin and the 3 edges passing through the origin, coincides with the positive direction of the axes...
Choose the correct answer from the given four options indicated against each of the Exercises if the distance between the points $(\mathrm{a}, 0,1)$ and $(0,1,2)$ is $\sqrt{27}$, then the value of $a$ is
(A) 5
(B) $\pm 5$
(C) 5
(D) none of these
Solution: Option(B) $\pm 5$ Explanation: Suppose $P$ be the point whose coordinate is $(a, 0,1)$ and $Q$ represents the point $(0,$, $(1,2) .$ It is given that, $\mathrm{PQ}=\sqrt{27}$ From the...
Choose the correct answer from the given four options indicated against each of the Exercises distance of the point $(3,4,5)$ from the origin $(0,0,0)$ is
(A) $\sqrt{50}$
(B) 3
(C) 4
(D) 5
Solution: Option (A) $\sqrt{50}$ Explanation: Suppose $\mathrm{P}$ be the point whose coordinate is $(3,4,5)$ and $\mathrm{Q}$ represents the origin. From the distance formula it can be written as...
Choose the correct answer from the given four options indicated against each of the Exercises what is the length of foot of perpendicular drawn from the point $P(3,4,5)$ on $y$-axis
(A) $\sqrt{41}$
(B) $\sqrt{34}$
(C) 5
(D) none of these
Solution: Option(B) $\sqrt{34}$ Explanation: As it is known that $y$-axis lies on $x$ y plane and $y z$. Therefore, its distance from $x y$ and $y z$ plane is 0 . $\therefore$ By the basic...
Choose the correct answer from the given four options indicated against each of the Exercises the distance of point P (3, 4, 5) from the y z-plane is
(A) 3 units
(B) 4 units
(C) 5 units
(D) 550
Solution: (A) 3 units Explanation: From basic ideas of three-dimensional geometry, it is known that $x$-coordinate of a point is its distance from $y z$ plane. $\therefore$ The distance of Point $P...
Prove that the points (0, – 1, – 7), (2, 1, – 9) and (6, 5, – 13) are collinear. Find the ratio in which the first point divides the join of the other two.
Solution: It is given that the three points $A(0,-1,-7), B(2,1,-9)$ and $C(6,5,-13)$ are collinear So it can be written as $\begin{array}{l} A...
The mid-point of the sides of a triangle are (1, 5, – 1), (0, 4, – 2) and (2, 3, 4). Find its vertices. Also find the centroid of the triangle.
Solution: It is given that the mid-point of the sides of a triangle are $(1,5,-1),(0,4,-2)$ and $(2,3,$, 4). Suppose the vertices be $A\left(x_{1}, y_{1}, z_{1}\right), B\left(x_{2}, y_{2},...
Show that the three points $A(2,3,4), B(-1,2,-3)$ and $C(-4,1,-10)$ are collinear and find the ratio in which $C$ divides $A B$.
Solution: It is given that the three points are A $(2,3,4), \mathrm{B}(-1,2,-3)$ and $\mathrm{C}(-4,1,-10)$ We need to find collinear points, $\begin{array}{l}...
Let A $(2,2,-3), B(5,6,9)$ and C $(2,7,9)$ be the vertices of a triangle. The internal bisector of the angle $A$ meets $B C$ at the point $D$. Find the coordinates of $D$.
Solution: It is given $A(2,2,-3), B(5,6,9)$ and $C(2,7,9)$ are the vertices of a triangle. And it is also given that the internal bisector of the angle A meets BC at the point D....
If the origin is the centroid of a triangle ABC having vertices A (a, 1, 3), B (– 2, b, – 5) and C (4, 7, c), find the values of a, b, c.
Solution: It is given that the triangle ABC having vertices $A(a, 1,3), B(-2, b,-5)$ and $C(4,7, c)$ and origin is the centroid. The coordinates of the centroid for a triangle is given by the...
Find the coordinate of the points which trisect the line segment joining the points A $(2,1,-3)$ and $\mathrm{B}$ $(5,-8,3)$
Solution: It is given the line segment joining the points are A $(2,1,-3)$ and $B(5,-8,3)$ Now suppose $P\left(x_{1}, y_{1}, z_{1}\right)$ and $Q\left(x_{2}, y_{2}, z_{2}\right)$ be the points which...
Three vertices of a Parallelogram ABCD are A (1, 2, 3), B (– 1, – 2, – 1) and C (2, 3, 2). Find the fourth vertex D.
Solution: It is given that the three consecutive vertices of a parallelogram ABCD are A $(1,2,3), B(-1,$, $-2,-1)$ and $C(2,3,2)$ Suppose the fourth vertex be $D(x, y, z)$. By using midpoint...
The mid-points of the sides of a triangle are (5, 7, 11), (0, 8, 5) and (2, 3, – 1). Find its vertices.
Solution: It is given that the mid-points of the sides of a triangle are $(5,7,11),(0,8,5)$ and $(2,3,-$ 1). Suppose the vertices be $A\left(x_{1}, y_{1}, z_{1}\right), B\left(x_{2}, y_{2},...
Find the centroid of a triangle, the mid-point of whose sides are $D(1,2,-3), E(3,0,1)$ and $F(-1,1,-$ 4).
Solution: It is given that: Mid-points of sides of triangle $\mathrm{DEF}$ are: $\mathrm{D}(1,2,-3), \mathrm{E}(3,0,1)$ and $\mathrm{F}(-1,1,-4)$ Using the geometry of centroid, It is known that the...
Find the third vertex of triangle whose centroid is origin and two vertices are (2, 4, 6) and (0, –2, –5).
Solution: It is given the centroid is origin and two vertices are $(2,4,6)$ and $(0,-2,-5)$ Suppose the third vertex be $(x, y, z)$ The coordinates of the centroid for a triangle is given by the...
Show that the triangle $\mathrm{ABC}$ with vertices $\mathrm{A}(0,4,1), \mathrm{B}(2,3,-1)$ and $\mathrm{C}(4,5,0)$ is right angled.
Solution: The given vertices are $A(0,4,1), B(2,3,-1)$ and $C(4,5,0)$ We need to prove right angled triangle, consider $\begin{array}{l}...
Three consecutive vertices of a parallelogram ABCD are A (6, – 2, 4), B (2, 4, – 8), C (–2, 2, 4). Find the coordinates of the fourth vertex.
Solution: The three consecutive vertices of a parallelogram $A B C D$ are as given $A(6,-2,4), B$ (2, $4,-8), C(-2,2,4)$ Suppose the forth vertex be $D(x, y, z)$ Midpoint of diagonal $A...
Show that the point $A(1,-1,3), B(2,-4,5)$ and $(5,-13,11)$ are collinear.
Solution: The given points are $A(1,-1,3), B(2,-4,5)$ and $(5,-13,11)$. We need to prove collinear, $\begin{array}{l} \mathrm{AB}=\sqrt{(1-2)^{2}+(-1+4)^{2}+(3-5)^{2}}=\sqrt{1+9+4}=\sqrt{14} \\...
Show that if $x^{2}+y^{2}=1$, then the point $\left(x, y \sqrt{1-x^{2}-y^{2}}\right)$ is at a distance 1 unit from the origin.
Solution: It is given that $x^{2}+y^{2}=1 \Rightarrow 1-x^{2}-y^{2}=0$ Distance of the point $\left(x, y \sqrt{1-x^{2}-y^{2}}\right)$ from origin is $=$ $\begin{array}{l}...
Find the distance from the origin to (6, 6, 7).
Solution: The distance from the origin to (6, 6, 7) $=\sqrt{{6^2}+{6^2}+{7^2}}$ $=\sqrt{{36}+{36}+{49}}$ $=\sqrt{121}$ $=11$ units
How far apart are the points (2, 0, 0) and (–3, 0, 0)?
Solution: The points $(2, 0, 0)$ and $(–3, 0, 0)$ are at a distance of $=$ $|2 − (−3)| = 5$ units.
Let A, B, C be the feet of perpendiculars from a point P on the xy, yz and zx planes respectively. Find the coordinates of A, B, C in each of the following where the point P is
(i) (4, – 3, – 5).
Solution: (i) $(4, – 3, – 5):- A (4, −3, 0), B (0, −3, −5), C (4, 0, −5)$
Let A, B, C be the feet of perpendiculars from a point P on the xy, yz and zx planes respectively. Find the coordinates of A, B, C in each of the following where the point P is
(i) (3, 4, 5)
(ii) (–5, 3, 7)
Solution: (i) $(3, 4, 5):- A (3, 4, 0), B (0, 4, 5), C (3, 0, 5)$ (ii) $(–5, 3, 7):- A (−5, 3, 0), B (0, 3, 7), C (−5, 0, 7)$
Let A, B, C be the feet of perpendiculars from a point P on the x, y, z-axis respectively. Find the coordinates of A, B and C in each of the following where the point P is :
(i) (4, – 3, – 5)
Solution: (i) $(4, – 3, – 5):- A (4, 0, 0), B (0, −3, 0), C (0, 0, −5)$
Let A, B, C be the feet of perpendiculars from a point P on the x, y, z-axis respectively. Find the coordinates of A, B and C in each of the following where the point P is :
(i) A = (3, 4, 2)
(ii) (–5, 3, 7)
Solution: (i) $(3, 4, 2):- A (3, 0, 0), B (0, 4, 0), C (0, 0, 2)$ (ii) $(–5, 3, 7):- A (−5, 0, 0), B (0, 3, 0), C (0, 0, 7)$
Name the octant in which each of the following points lies.
(i) (2, – 4, – 7)
(ii) (– 4, 2, – 5).
Solution: (i) $(2, – 4, – 7)$:- 8th Octant, (ii) $(– 4, 2, – 5)$:- 6th Octant.
Name the octant in which each of the following points lies.
(i) (– 4, 2, 5)
(ii) (–3, –1, 6)
Solution: (i) $(– 4, 2, 5)$:- 2nd Octant, (ii) $(–3, –1, 6)$:- 3rd Octant,
Name the octant in which each of the following points lies.
(i) (4, –2, –5)
(ii) (4, 2, –5)
Solution: (i) $(4, –2, –5)$:- 8th Octant, (ii) $(4, 2, –5)$:- 5th Octant,
Name the octant in which each of the following points lies.
(i) (1, 2, 3),
(ii) (4, – 2, 3),
Solution: (i) $(1, 2, 3)$:- 1st Octant, (ii) $(4, – 2, 3)$:- 4th Octant,
Locate the following points:
(i) (– 2, – 4, –7)
(ii) (– 4, 2, – 5).
Solution: (i) $(– 2, – 4, –7)$:- 7th octant, (ii) $(– 4, 2, – 5)$:- 6th octant.
Locate the following points:
(i) (1, – 1, 3),
(ii) (– 1, 2, 4)
Solution: (i) $(1, – 1, 3)$:- 4th octant, (ii) $(– 1, 2, 4)$:- 2nd octant,