English

Answer the following: If a2 + b2 = 7ab, show that, log(a+b3)=12loga+12logb - Mathematics and Statistics

Advertisements
Advertisements

Question

Answer the following:

If a2 + b2 = 7ab, show that, `log(("a" + "b")/3) = 1/2 log "a" + 1/2 log "b"`

Sum

Solution

a2 + b2 = 7ab

∴ a2 + b2 + 2ab = 7ab + 2ab

∴ (a + b)2 = 9ab

∴ `("a" + "b")^2/9` = ab

∴ `(("a" + "b")/3)^2` = ab

∴ `log(("a" + "b")/3)^2` = log (ab)

∴ `2log(("a" + "b")/3)` = log a + log b

∴ `log(("a" + "b")/3) = 1/2 log"a" + 1/2log"b"`

shaalaa.com
  Is there an error in this question or solution?
Chapter 6: Functions - Miscellaneous Exercise 6.2 [Page 131]

APPEARS IN

RELATED QUESTIONS

Let A = {−2, −1, 0, 1, 2} and f : A → Z be a function defined by f(x) = x2 − 2x − 3. Find:

(b) pre-images of 6, −3 and 5.

 

Let f : R+ → R, where R+ is the set of all positive real numbers, such that f(x) = loge x. Determine

(a) the image set of the domain of f


If f(x) = (x − a)2 (x − b)2, find f(a + b).

 

If  \[y = f\left( x \right) = \frac{ax - b}{bx - a}\] , show that x = f(y).

 

 


Let f and g be two real functions defined by \[f\left( x \right) = \sqrt{x + 1}\] and \[g\left( x \right) = \sqrt{9 - x^2}\] . Then, describe function: 

(iv) \[\frac{f}{g}\]

 

Write the domain and range of the function  \[f\left( x \right) = \frac{x - 2}{2 - x}\] .

 

If f : Q → Q is defined as f(x) = x2, then f−1 (9) is equal to


If f(x) = sin [π2x + sin [−π]2 x, where [x] denotes the greatest integer less than or equal to x, then


The domain of definition of the function \[f\left( x \right) = \sqrt{\frac{x - 2}{x + 2}} + \sqrt{\frac{1 - x}{1 + x}}\] is 

 

Check if the following relation is function:


A function f is defined as follows: f(x) = 4x + 5, for −4 ≤ x < 0. Find the values of f(−1), f(−2), f(0), if they exist.


If f(x) = `{(x^2 + 3","  x ≤ 2),(5x + 7","  x > 2):},` then find f(0)


Check if the following relation is a function.


Which sets of ordered pairs represent functions from A = {1, 2, 3, 4} to B = {−1, 0, 1, 2, 3}? Justify.

{(1, 0), (3, 3), (2, −1), (4, 1), (2, 2)}


Check if the relation given by the equation represents y as function of x:

2x + 3y = 12


Check if the relation given by the equation represents y as function of x:

x2 − y = 25


If f(m) = m2 − 3m + 1, find `(("f"(2 + "h") - "f"(2))/"h"), "h" ≠ 0`


Find x, if g(x) = 0 where g(x) = `(5x - 6)/7`


Find x, if g(x) = 0 where g(x) = `(18 -2x^2)/7`


Find the domain and range of the following function.

g(x) = `(x + 4)/(x - 2)`


lf f(x) = 3(4x+1), find f(– 3)


Express the following logarithmic equation in exponential form

In `1/2` = – 0.693


If `log((x + y)/3) = 1/2 log x + 1/2 logy`, show that `x/y + y/x` = 7


Select the correct answer from given alternative.

The domain and range of f(x) = 2 − |x − 5| is


Answer the following:

Let f: R → R be a function defined by f(x) = 5x3 – 8 for all x ∈ R, show that f is one-one and onto. Hence find f –1 


Answer the following:

Show that, `log |sqrt(x^2 + 1) + x | + log | sqrt(x^2 + 1) - x|` = 0


Answer the following:

Show that `7log (15/16) + 6log(8/3) + 5log (2/5) + log(32/25)` = log 3


Answer the following:

Solve : `sqrt(log_2 x^4) + 4log_4 sqrt(2/x)` = 2


Find the domain of the following function.

f(x) = `sqrtlog(x^2 - 6x + 6)`


Answer the following:

Find the range of the following function.

f(x) = `x/(9 + x^2)`


Answer the following:

Find the range of the following function.

f(x) = 1 + 2x + 4x 


A function f is defined by f(x) = 2x – 3 find x such that f(x) = 0


The data in the adjacent table depicts the length of a person's forehand and their corresponding height. Based on this data, a student finds a relationship between the height (y) and the forehand length (x) as y = ax + b, where a, b are constant.

Length ‘x’ of
forehand (in cm)
Height 'y' 
(in inches)
35 56
45 65
50 69.5
55 74

Check if this relation is a function


Let A = {1, 2, 3, 4} and B = N. Let f : A → B be defined by f(x) = x3 then, find the range of f


If a function f(x) is given as f(x) = x2 – 6x + 4 for all x ∈ R, then f(–3) = ______.


Let A and B be any two sets such that n(B) = p, n(A) = q then the total number of functions f : A → B is equal to ______.


If f(x) = `(x - 1)/(x + 1)`, then show that `f(- 1/x) = (-1)/(f(x))`


The domain of the function f given by f(x) = `(x^2 + 2x + 1)/(x^2 - x - 6)` is ______.


The period of the function

f(x) = `(sin 8x cos x - sin 6x cos 3x)/(cos 2x cos x - sin 3x sin 4x)` is ______.


Share
Notifications

Englishहिंदीमराठी


      Forgot password?
Use app×