Question

Check whether the following statements are true or false. Justify your answer with a short explanation or a counter example.

(i) The numbers equation are the direction cosines of a line.

(ii) The points (1, 2), (7, 6) and (4, 4) are collinear.

(iii) The conic 12x² + 12xy + 3y² + 2x + y = 0 is degenerate.

(iv) Intersection of the ellipsoid x/4+ y2 /25+ z2 /4 = 1 and the plane y = 5 is a circle. 

(v) The conicoid 3x² + y² + 2xy+x-y-z+1=0 is non-central.

(vi) The line y = x is a tangent to the parabola y² = cx, c > 0.

(vii) The equation 2x² + y + z + 1 = 0 represents a paraboloid.

(viii) Projection of a line segment on a line perpendicular to it is the length of the line segment.

(ix) The lines x =- y, z = 2 and x = y, z = 0 intersect each other.

(x) Every planar section of a cylinder is a circle.

17 Feb 2025
Answer :
Word Count : 765
Let's break down each statement and solve it one by one. ### (i) The numbers \( \frac{1}{\sqrt{2}}, \frac{1}{\sqrt{3}}, \frac{3}{4} \) are the direction cosines of a line. False. The direction cosines of a line must satisfy the condition: \[ l^2 + m^2 + n^2 = 1 \] where \(l\), \(m\), and \(n\) are the direction cosines. For the given numbers, \[ \left(\frac{1}{\sqrt{2}}\right)^2 + \left(\frac{1}{\sqrt{3}}\right)^2 + \left(\frac{3}{4}\right)^2 = \frac{1}{2} + \frac{1}{3} + \frac{9}{16} = 0.5 + 0.3333 + 0.5625 = 1.3958 \neq 1. \] Thus, they do not satisfy the condition for direction cosines. ### (ii) The points (1, 2), (7, 6), and (4, 4) are collinear. False. To check if three points are collinear, we can compute the area of the triangle formed by them. If the area is zero, the points are collinear. Using the determinant method: \[ \text{Area} = \frac{1}{2} \left| x_1(y_2 - y_3) + x_2(y_3 - y_1) + x_3(y_1 - ________ ______ _________ ________ _______ _____ ________ ____ ____.
______ ____ ________ _______ _________ __________ _____ _________ _________ _____.
________ ______ _____ _____ ____ _______.
______ _____ _________ _______ __________ __________ ______ ________ _______ ___.
____ _________ __________ ______ ______ _________ ____.
_____ _____ ___ _______ _________.
__________ ______ _________ ____ __________ ______.
______ _____ ___ ____ __________ __________ ________.
_____ __________ _______ ___ _____ ________ ___ ___ __________ ____ ______.
________ ___ _____ ___ _______ _________ _____ _________ ______ ______.
___ ______ ___ ________ ______ ________ _____ ______.
___ ______ _____ _________ ______ ____ __________.
_________ ______ __________ ________ __________ ___ ___ __________ _____.
______ ________ ___ __________ ____ ____.
_______ __________ _______ ____ ______ ______.
__________ ____ ___ __________ ___ _______ ______ ______ __________ ______ __________ ________.
______ ______ ____ ______ _____ ________ ___ __________ _______.
________ ___ _________ _____ _________ __________ _______ _________ ______.
______ ________ _______ ___ _________ ________ __________ _________ ___ ________ _________.
__________ ______ _______ _______ __________ _________ ________ _________ _______.
__________ ____ _________ ________ _________ ______ ____ _________ _________ __________ ________ _____.
_______ __________ ____ ________ _____ _______ ________ ____ _______ ______.
____ _______ _______ ____ ______.
_______ ___ ____ _____ ___.
__________ ____ ________ __________ ____ ___ __________ ________ ____ ___.
_____ _____ _____ ____ ______ _______ _______ ______ ______.
_______ _____ ________ _________ ______ _____ ____ ___ ________ __________.
___ ___ ______ _____ ________ _____ ___ ________ ___ ____ _____ ____.
_______ _______ ________ _____ __________ ________ _____ ___ _____.
___ ____ _______ ____ __________ ___ ________ _____ ____ _________ ________.
___ ________ ________ _____ __________ __________ ______ _______.
_________ ________ ______ _____ _______ _______ ______ __________ ____ ____ __________ ___.
________ ______ _________ ___ __________.
_____ _________ _________ ________ _______ ___.
______ __________ _____ ________ ________ _______ _______ ______ _______ ___ ______.
______ _______ __________ ________ _____ _________ ____ _______ _______ ________ ____.
_____ _____ ______ __________ _______ _________ _________ __________ ___ _________ ______ ____.
_________ ____ ________ ____ _______ ________.
_____ ____ _____ _______ ______ ______ __________ __________.
______ _________ ________ ____ ________ ____ _____ ____ _________ __________.
___ ________ ______ _________ __________.
_________ ______ ___ __________ _________ _____.
__________ ____ ______ ________ _________ ____ ___.
________ ________ _____ _______ ___ ____ __________ ________ __________ _________ ________ _____.
______ ________ _______ ________ __________.
___ ____ _______ __________ __________ _____ __________ ___ ___ _________.
______ ____ _______ __________ _______ ________ _____.
________ _________ _______ _________ ____ _________ __________ _______ _____ ___ _____ ___.
_______ ________ _______ __________ ________ ________ ____ ___ ________.
_______ _____ _______ __________ _____ ___ _________ ________ ______ ______.
_________ _______ _______ ________ _____ _____ _______.
__________ ______ ________ _______ ___ ____ _________ ______.
_________ ______ ______ __________ _________ ______ _________ ______ __________ ___ ________ __________.
_____ _________ _______ _______ ______ _____ _______ ________ ______ ______ ______ _____.
______ ______ ____ ___ __________ ______ _________ ____ ________ ________.
___ __________ _______ ___ _____ _____.
_________ ______ ___ _________ ______ ____ ___ __________ _______ ________.
____ ______ ______ _________ _____ ___ ________.
____ __________ __________ ________ ________.
_________ ______ __________ ________ _______ ________.
______ ___ ______ ____ ______ _____ __________ _______ _________ _________ ___.
__________ ______ ____ _______ ___ ___ _________ _________ ________ ____ ______.
________ ___ _______ _________ _____ _____ ___ _______ _______ ____ _____ __________.
________ __________ _______ ___ ___ _________ ________.
___ __________ ____ _________ ____ _____ __________ ________ _____ _____ ____ _________.
__________ _________ ________ __________ _______ ______ ___ ________ ____ ___.
_______ _______ __________ _____ _____ ____ ______ ________ _______ ___.
______ _____ ___ ____ ____ ________ ________ _________ _____ ______ _____.
___ ______ ___ _______ ________ ______.
________ _______ ___ _______ __________ ______ ______.
Get Full Answer on WhatsApp
IGNOU NEWS
Assignment Submission Last Date Extended Till 30 June 2026 Click Here★★★IGNOU June 2026 TEE Date Sheet Released Click Here★★★
Top
📞
Call Support Instant phone assistance Check whether the following statements are true or false. Justify your
🟢
WhatsApp Chat Fast live messaging
Email Us Business enquiries & support