\(cos^{-1}\frac{2}{3}\)
Let α,β be the roots of the equation, ax2+bx+c=0.a,b,c are real and sn=αn+βn and \(\begin{vmatrix}3 &1+s_1 &1+s_2\\1+s_1&1+s_2 &1+s_3\\1+s_2&1+s_3 &1+s_4\end{vmatrix}=\frac{k(a+b+c)^2}{a^4}\) then k=
A line is one example of a one-dimensional figure, which has length but no width. A line is made up of a set of points that is stretched in opposite directions infinitely.
Similarly, when an infinite number of points expanded infinitely in either direction to form a flat surface, it is known as a plane. A set of lines when arranged close by to each other a plane is obtained. A plane is one example of a two-dimensional geometric figure that can be measured in terms of length and width.
The line which is adjacent to the plane is the complement of the angle between and the normal of the plane is called the angle between a line and a plain.