Recent questions tagged determinants

Inverse of the matrix $\begin{bmatrix}\cos 2\theta&-\sin 2\theta\\\sin 2\theta&\cos 2\theta\end{bmatrix}$ is

asked Nov 22, 2013 by sreemathi.v

1 answer

If $\begin{vmatrix}x^n&x^{n+2}&x^{n+3}\\y^n&y^{n+2}&y^{n+3}\\z^n&z^{n+2}&z^{n+3}\end{vmatrix}$ = $(y-z)(z-x)(x-y)(\large\frac{1}{x}+\frac{1}{y}+\frac{1}{z})$ then $n$ is equal to

asked Nov 22, 2013 by sreemathi.v

1 answer

If $A=\begin{bmatrix}1&x\\x^2&4y\end{bmatrix}$ and $B=\begin{bmatrix}-3&1\\1&0\end{bmatrix}$ and adj$(A+B)=\begin{bmatrix}1 &0\\0&1\end{bmatrix}$ then values of $x$ and $y$ are

asked Nov 22, 2013 by sreemathi.v

1 answer

If $C=2\cos \theta$ then the value of the determinant $\Delta=\begin{vmatrix}c&1&0\\1&c&1\\6&1&c\end{vmatrix}$ is

asked Nov 22, 2013 by sreemathi.v

1 answer

If one root of the determinant $\begin{vmatrix}x&3&7\\2&x&2\\7&6&x\end{vmatrix}=0$ is $-9$ then the other two roots are

asked Nov 22, 2013 by sreemathi.v

1 answer

Let $a,b,c$ be any real numbers. Suppose that there are real numbers $x,y,z$ not all zero. Such that $x=cy+bz,y=az+cx,z=bx+ay$. Then $a^2+b^2+2abc$ is equal to

asked Nov 22, 2013 by sreemathi.v

1 answer

If $a_1,a_2,a_3.....a_n$ are in G.P then the determinant $\Delta=\begin{vmatrix}\log a_n&\log a_{n+1}& \log a_{n+2}\\\log a_{n+3}&\log a_{n+4}&\log a_{n+5}\\\log a_{n+6}&\log a_{n+7}&\log a_{n+8}\end{vmatrix}$ is equal to

asked Nov 22, 2013 by sreemathi.v

1 answer

If $a^2+b^2+c^2=-2$ and $f(x)=\small\begin{vmatrix}1+a^2x&(1+b^2)x&(1+c^2)x\\(1+a^2)x&1+b^2x&(1+c^2)x\\(1+a^2)x&(1+b^2)x&1+c^2x\end{vmatrix}$ then $f(x)$ is a polynomial of degree

asked Nov 22, 2013 by sreemathi.v

1 answer

The system of equations $\alpha x+y+z=\alpha-1$, $x+\alpha y+z=\alpha-1$, $x+y+\alpha z=\alpha-1$ has infinite solutions if $\alpha$ is

asked Nov 22, 2013 by sreemathi.v

1 answer

$A=\begin{bmatrix}1&0&0\\0&1&1\\0&-2&4\end{bmatrix}$ and $I=\begin{bmatrix}1&0&0\\0&1&0\\0&0&1\end{bmatrix}$ and $A^{-1}=[\large\frac{1}{6}$$(A^2+cA+dI)]$ then the value of $c$ and $d$ are

asked Nov 22, 2013 by sreemathi.v

1 answer

The parameter on which the value of the determinant $\begin{vmatrix}1&x&x+1\\\cos(p-d)x&\cos px&\cos(p+d)x\\\sin(p-d)x&\sin px&\sin(P+d)x\end{vmatrix}$ does not defined upon is

asked Nov 22, 2013 by sreemathi.v

1 answer

For positive numbers $x,y$ and $z$ the numerical value of the determinant $\begin{vmatrix}1 &\log_xy&\log_xz\\\log_yx&1&\log_yz\\\log_zx&\log_zy&1\end{vmatrix}$ is

asked Nov 21, 2013 by sreemathi.v

1 answer

Let $a,b,c$ be the real numbers. Then the following system of equations in $x,y$ and $z$: $\large\frac{x^2}{a^2}+\frac{y^2}{b^2}-\frac{z^2}{c^2}=1$, $\large\frac{x^2}{a^2}-\frac{y^2}{b^2}+\frac{z^2}{c^2}=1$, $\large\frac{-x^2}{a^2}+\frac{y^2}{b^2}+\frac{z^2}{c^2}=1$ has

asked Nov 21, 2013 by sreemathi.v

1 answer

Let $p\lambda^4+q\lambda^3+r\lambda^2+s\lambda+t$ = $\begin{vmatrix}\lambda^3+3\lambda&\lambda-1&\lambda+3\\\lambda+1&-2\lambda&\lambda-4\\\lambda-3&\lambda+4&3\lambda\end{vmatrix}$ be an identity in $\lambda$ where $p,q,r,s$ and $t$ are constant. Then the value of $t$ is

asked Nov 21, 2013 by sreemathi.v

1 answer

If $B$ is a non-singular matrix and A is a square matrix then $det(B^{-1}AB)$ is equal to

asked Nov 21, 2013 by sreemathi.v

1 answer

If $a_1,a_2,a_3.......a_n$ are in G.P then the value of the determinant $\begin{vmatrix}\log a_n&\log a_{n+1}&\log a_{n+2}\\\log a_{n+3}&\log a_{n+4}&\log a_{n+5}\\\log a_{n+6}&\log a_{n+7}&\log a_{n+8}\end{vmatrix}$ is

asked Nov 21, 2013 by sreemathi.v

1 answer

If $D=\begin{vmatrix}1&1&1\\1&1+x&1\\1&1&1+y\end{vmatrix}$ for $x\neq 0,y\neq 0$ then $D$ is

asked Nov 21, 2013 by sreemathi.v

1 answer

If $A^2-A+I=0$ then the inverse of A is

asked Nov 21, 2013 by sreemathi.v

1 answer

Let $A=\begin{bmatrix}1 &-1&1\\2&1&-3\\1&1&1\end{bmatrix}$ and $10B=\begin{bmatrix}4 &2&2\\-5&0&\alpha\\1&-2&3\end{bmatrix}$ if $B$ is the inverse of matrix A then $\alpha$ is

asked Nov 21, 2013 by sreemathi.v

1 answer

Let $A=\begin{bmatrix}0 &0&-1\\0&-1&0\\-1&0&0\end{bmatrix}$.The only correct statement about the matrix A is

asked Nov 21, 2013 by sreemathi.v

1 answer

If $1,\omega,\omega^2$ are the cube roots of unity ,then $\Delta=\begin{vmatrix}1&\omega^n&\omega^{2n}\\\omega^{2n}&1&\omega^n\\\omega^{2n}&1&\omega^n\end{vmatrix}$ is equal to

asked Nov 21, 2013 by sreemathi.v

1 answer

If the system of linear equations $x+2ay+az=0,x+3by+bz=0,x+4cy+cz=0$ has a non-zero solution the a,b,c

asked Nov 21, 2013 by sreemathi.v

1 answer

If $a>0$ and determinant of $ax^2+2bx+c$ is -ve then $\begin{vmatrix}a&b&ax+b\\b&c&bx+c\\ax+b&bx+c&0\end{vmatrix}$ is equal to

asked Nov 21, 2013 by sreemathi.v

1 answer