Answer

Verified

412.8k+ views

**Hint:**At first, we have to convert ${\log _{10}}$ in the base index of 2. And then we need to simplify the whole part. In this way, we will convert ${\log _{10}}\sqrt {32} $ in the base index of 2 and simplify the whole part. For the third question we have to use the formula of logarithm.

**Complete step-by-step answer:**

According to the question

${\log _{10}}8 = {\log _{10}}{2^3}$ [ As $8 = {2^3}$]

$ = 3.\log {10^2}$

From the values given in the question, we have

$\therefore 3{\log _{10}}2 = 0.90{\text{ (as per question)}}$

Solving it,

$ \Rightarrow {\log _{10}}2 = 0.3$…..(1)

(i) ${\log _{10}}4$

$ = {\log _{10}}{2^2}$ [We know $4 = {2^2}$ so by putting the value in the next step]

$ = 2.{\log _{10}}2{\text{ }}...{\text{(1)}}$ $\left[ \begin{gathered}

{\text{We know}} \\

{\text{lo}}{{\text{g}}_e}{a^b} = b{\log _e}a \\

\end{gathered} \right]$

So, ${\log _{10}}4 = 2.{\log _{10}}2{\text{ from (1)}}$

$ = 2 \times \left( {0.3} \right) = 0.6{\text{ }}...{\text{(2)}}$

(2) ${\log _{10}}\sqrt {32} $

$ = {\log _{10}}{\left( {32} \right)^{\dfrac{1}{2}}}{\text{ }}\left[ \begin{gathered}

{\text{We know}} \\

{\text{lo}}{{\text{g}}_e}{a^b} = b{\log _e}a \\

\end{gathered} \right]$

Applying the rule, we get

$ = \dfrac{1}{2}{\log _{10}}32$

$ = \dfrac{5}{2}{\log _{10}}2$

Thus, after simplification and value from eqn (2), we get

$ = \dfrac{5}{2} \times 0.3 = 0.75 {\text{ }}\left[ {{\text{from (1)}}} \right]$

(3) ${\log _{10}}0.125$

$ = {\log _{10}}\left( {\dfrac{{125}}{{1000}}} \right)$

(since$0.125 = \dfrac{{125}}{{1000}}$)

Solving it, we get

${\log _e}\left( {a/b} \right) = {\log _e}a - {\log _e}b$$ = {\log _{10}}\left( {\dfrac{1}{8}} \right){\text{ }}\left[ \begin{gathered}

{\text{We know}} \\

{\log _e}\left( {a/b} \right) = {\log _e}a - {\log _e}b \\

\end{gathered} \right]$

$ = {\log _{10}}1 - {\log _{10}}8$

$ = - 0.90$ (since ${\log _{10}}1 = 0$and ${\log _{10}}8 = 0.90$)

Thus solution is:

$\begin{gathered}

{\log _{10}}4 = 0.6 \\

{\log _{10}}\sqrt {32} = 1.5 \\

{\log _{10}}0.125 = - 0.90 \\

\end{gathered} $

**Additional Information:**Logarithm is the inverse function to exponentiation. That means the logarithm of a given number x is the exponent to which another fixed number, the base b, must be raised, to produce that number x. In the simplest case, the logarithm counts the number of occurrences of the same factor in repeated multiplication; e.g., since \[1000{\text{ }} = {\text{ }}10\, \times \,10\, \times \,10{\text{ }} = {\text{ }}{10^3}\], the “\[logarithm{\text{ }}base{\text{ }}10\]" of \[1000\] , or \[lo{g_{10}}\left( {1000} \right){\text{ }} = {\text{ }}3\] \[lo{g_{10}}\left( {10} \right){\text{ }} = {\text{ }}3\].

Logarithms are also of various representation type,

Common logarithm: The common logarithm has \[base{\text{ }}10\], and is represented on the calculator as log(x).

Natural logarithm: The natural logarithm has \[base{\text{ }}e\], a famous irrational number, and is represented on the calculator by ln(x). The natural and common logarithm can be found throughout Algebra and Calculus.

**Note:**We have to be careful about the index because we all have to change the index of the given one and the one which we have to find. Do the calculative portion carefully to ensure that there would be no mistake instead of knowing the concept & formulas. Formulas used in the above questions are;

\[{\text{lo}}{{\text{g}}_e}{a^b} = b{\log _e}a\]

${\log _e}\left( {a/b} \right) = {\log _e}a - {\log _e}b$

Recently Updated Pages

Find the value of cos 260 circ sin 230 circ + tan 230 class 10 maths CBSE

How do you identify dfrac1cot2x + 1 class 10 maths CBSE

Evaluate the following sin 30circ cos 30circ class 10 maths CBSE

What will be the area of the triangle formed by the class 10 maths CBSE

Find the missing number in the pattern 2581117202326 class 10 maths CBSE

What is the standard form of y left 2x 3 right2 class 10 maths CBSE

Trending doubts

Difference Between Plant Cell and Animal Cell

Give 10 examples for herbs , shrubs , climbers , creepers

Fill the blanks with the suitable prepositions 1 The class 9 english CBSE

Difference between Prokaryotic cell and Eukaryotic class 11 biology CBSE

Write a letter to the principal requesting him to grant class 10 english CBSE

Change the following sentences into negative and interrogative class 10 english CBSE

Write the 6 fundamental rights of India and explain in detail

Name 10 Living and Non living things class 9 biology CBSE

The Equation xxx + 2 is Satisfied when x is Equal to Class 10 Maths