Question
$\begin{vmatrix}\log_3512&\log_43\\\log_38&\log_49\end{vmatrix}\times\begin{vmatrix}\log_23&\log_83\\\log_34&\log_34\end{vmatrix}$
  1. 7
  2. 10
  3. 1
  4. 17

Answer

  1. 10
Solution:
$\begin{vmatrix}\log_3512&\log_43\\\log_38&\log_49\end{vmatrix}\times\begin{vmatrix}\log_23&\log_83\\\log_34&\log_34\end{vmatrix}$
$=\begin{vmatrix}\log_32^9&\log_{2^{2}}3\\\log_32^3&\log_{2^2}3^3\end{vmatrix}\times\begin{vmatrix}\log_23&\log_{2^{3}}3\\\log_32^3&\log_32^2\end{vmatrix}$
$=\begin{vmatrix}9\log_32&\frac{1}{2}\log_23\\3\log_32&\frac{1}{2}\times2\log_23\end{vmatrix}\times\begin{vmatrix}\log_23&\frac{1}{3}\log_23\\2\log_32&2\log_32\end{vmatrix}$
$=\Big(\big(9\log_32\times\log_23\big)-\big(3\log_32\times\frac{1}{2}\log_23\big)\Big)\times\Big(\big(\log_23\times2\log_32\big)\\-\Big(\frac{1}{3}\log_23\times2\log_32\Big)\Big)$
$=\Big(9-\frac{3}{2}\Big)\times\Big(2-\frac{2}{3}\Big)$
$=\frac{15}{2}\times\frac{4}{3}$
$=10$

Need a full question paper?

Generate a complete, print-ready paper with questions like this in minutes — across 16+ boards, with answer keys.

Start Generating Free

Similar questions

The sine of the angle between the straight line $\frac{\text{x}-2}{3}=\frac{\text{y}-3}{4}=\frac{\text{z}-4}{5}$ and the plane 2x - 2y + z = 5 is:
The corner points of the feasible region are A(0, 0), B(16, 0), C(8, 16) and D(0, 24). The minimum value of the objective function z = 300x + 190y is _______:
  1. 5440
  2. 4800
  3. 4560
  4. 0
One hundred idential coins, each with probability p of showing heads are tossed once. If 0 < p < 1 and the probability of heads showing on 50 coins is equal to that of heads showing on 51 coins, the value of p is:
  1. $\frac{1}{2}$
  2. $\frac{51}{101}$
  3. $\frac{49}{101}$
  4. $\text{None of these}$
The equation of the plane passing through the points (3, 2, −1), (3, 4, 2) and (7, 0, 6) is 5x + 3y −2z = λ where λ is:
In $\triangle A B C, \overrightarrow{A B}=\hat{i}+\hat{j}+2 \hat{k}$ and $\overrightarrow{A C}=3 \hat{i}-\hat{j}+4 \hat{k}$. If $D$ is mid-point of $B C$, then vector $\overrightarrow{A D}$ is equal to:
The integrating factor of differential equation $\cos x \frac{d y}{d x}+ y \sin x =1$ is
If $\vec{\text{a}},\vec{\text{b}},\vec{\text{c}}$ and $\vec{\text{d}}$ are the position vector of points A, B, C, D such that no three of them are collinear and $\vec{\text{a}}+\vec{\text{c}}=\vec{\text{b}}+\vec{\text{d}}$, then ABCD is a,
  1. Rhombus.
  2. Rectangle.
  3. Square.
  4. Parallelogram.
If $\text{A}_{\text{r}}=\begin{vmatrix}1&\text{r}&2^{\text{r}}\\2&\text{n}&\text{n}^{2}\\\text{n}&\frac{\text{n}(\text{n}+1)}{2}&2^{\text{n}+1} \end{vmatrix},$ then the value of $\sum\limits_{\text{r}=1}^\text{n}\text{A}_\text{r}$ is:
The area $($in sq. units$)$ enclosed between the graph of $y = x^3$ and the lines $x = 0, y = 1, y = 8$ is$:$
The order of $\begin{bmatrix}\text{x}&\text{amp;}\text{ y}&\text{amp; }\text{z}\end{bmatrix}$ $\begin{bmatrix}\text{x} &\text{amp;}\text{ h}&\text{amp;}\text{ g} \\\text{h} &\text{amp;}\text{ b}&\text{amp; }\text{f}\\\text{g} &\text{amp;}\text{ f}&\text{amp; }\text{c} \end{bmatrix}\begin{bmatrix}\text{x}\\\text{y}\\\text{z}\end{bmatrix}$ is:
  1. $3\times1$
  2. $1\times1$
  3. $1\times3$
  4. $3\times3$