I. Let P (x, y) be any point on the line joining points A (1, 2) and B (3, 6). Then, the points A, B, and P are collinear.
Therefore, the area of triangle ABP will be zero.
\(\frac{1}{2}\)\(\begin{vmatrix}1&2&1\\3&6&1\\x&y&1\end{vmatrix}\)=0
\(\Rightarrow\)\(\frac{1}{2}\)[1(6-y)-2(3-x)+1(3y-6x)]
=6-y-6+2x+3y-6x=0
\(\Rightarrow\) y=2x
Hence, the equation of the line joining the given points is y = 2x.
II. Let P (x, y) be any point on the line joining points A (3, 1) and B (9, 3). Then, the points A, B, and P are collinear.
Therefore, the area of triangle ABP will be zero.
\(\frac{1}{2}\)\(\begin{vmatrix}3&1&1\\9&3&1\\x&y&1\end{vmatrix}\)
\(\Rightarrow\)\(\frac{1}{2}\)[3(3-y)-1(9-x)+1(9y-3x)]
\(\Rightarrow\) 9-3y-9+x+9y-3x=0
\(\Rightarrow\) x-3y=0
Hence, the equation of the line joining the given points is x − 3y = 0
Determine whether each of the following relations are reflexive, symmetric, and transitive.
Show that the relation R in the set R of real numbers, defined as
R = {(a, b): a ≤ b2 } is neither reflexive nor symmetric nor transitive.
Check whether the relation R defined in the set {1, 2, 3, 4, 5, 6} as
R = {(a, b): b = a + 1} is reflexive, symmetric or transitive.
Evaluate the determinants in Exercises 1 and 2.
\(\begin{vmatrix}2&4\\-5&-1\end{vmatrix}\)
Evaluate the determinants in Exercises 1 and 2.
(i) \(\begin{vmatrix}\cos\theta&-\sin\theta\\\sin\theta&\cos\theta\end{vmatrix}\)
(ii) \(\begin{vmatrix}x^2&-x+1&x-1\\& x+1&x+1\end{vmatrix}\)
Using properties of determinants,prove that:
\(\begin{vmatrix} x & x^2 & 1+px^3\\ y & y^2 & 1+py^3\\z&z^2&1+pz^3 \end{vmatrix}\)\(=(1+pxyz)(x-y)(y-z)(z-x)\)
Using properties of determinants,prove that:
\(\begin{vmatrix} 3a& -a+b & -a+c\\ -b+a & 3b & -b+c \\-c+a&-c+b&3c\end{vmatrix}\)\(=3(a+b+c)(ab+bc+ca)\)