Exponential Formula: Definition, Explanation

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Jasmine Grover

Education Journalist | Study Abroad Lead

Exponentiation Functions and exponentiation formulas are widely used in Mathematics to perform complex calculations with large numbers. It also represents the rapid growth of a given dependent variable with a few independent variables. In general, the exponential function represents the high growth rate. Even in Physics and Chemistry, these functions are very useful and important. Moreover, it can be seen that as the exponent increases, the curves become steeper, respectively, and the growth rate increases. 

Key Terms: Exponentiation Function, Exponentiation Formulas, Variable, Exponents, Constant, Coefficient, Real Numbers, Independent Variables, Compound Interest

Also read: Isosceles Triangle Theorems


What is the Exponential Function? 

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As the name of an exponential is defined, it involves an exponent. This exponent is diagrammatical employing a variable instead of a constant. On the opposite hand, its base is represented with constant worth rather than a variable. 

\(f(x) = ab^x\)

This is an exponential function where “b” is a constant, the exponent “x” is the independent variable i.e. input of the function. The coefficient “a” is called the initial value of the function, f(x) represents the dependent variable i.e. output of the function. Thus for x>1, the value of f(x) will always increase for increasing values of x. The exponential property can be used to solve the equations with exponential functions. Exponential functions that are defined by an equation of the form are called exponential decay functions if the change factor b follows the inequality 0 < b < 1. 

Exponential Equation

Exponential Equation

Exponential capabilities are used to version the boom of populations, carbon date artifacts, assist coroners to decide the time of death, compute the investments and compound interest, decay fee of radioactive factors in addition to many different applications. 

The video below explains this:

Exponential Formula Detailed Video Explanation:

Read More: Difference Between Power And Exponent


Formula of Exponential Function

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If a is a number such that a>0 and a ≠ 1 an exponential function is a function in the form, 

\(f(x) = ab^x\)

Where a is the base and x can be any real number 


Some Basic Formulas of Exponential Function

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Many useful formulas are available for exponential mathematics functions. Some of these formulas are as follows:

Here x and y are variables and a, b, m, n are constants

  • Adding the Exponents

\(x^a * x^b = x^{a+b}\)

  • Subtracting the Exponents

\(\frac{x^a}{x^b} = x^{a-b}\)

  • Getting Exponents of Exponents

\((x^a)b) = ((x^a)b)\)

  • Expanding Exponents of Products

\((xy)^a = x^a * y^a\)

  • Giving Value for Zero Exponent

X0 = 1

  • Giving Value for Unit Exponent

\(x^1 = x\)

  • Giving Value of Negative Exponent

\((x^-(^n) = \frac{1}{x^n}\)

  • Giving Value of Fractional Exponent

\(x^{\frac{m}{n}} = \sqrt[n]{x^m}\)

Laws of Exponents

Laws of Exponents

Read More: Powers and Negative Exponents


Things to Remember 

  • Exponentiation functions and exponentiation formula are very useful in Maths for the computation of complex computations with large numbers.
  • The exponential function depicts the high growth rate in general. 
  • In exponential function, the exponent is represented using a variable instead of a constant.
  • The base in exponential function is represented with constant value rather than a variable.
  • There are numerous useful formulas used for exponential functions which are directly used to get values of unknown variables.

Also read: Calculus Formula


Solved Questions 

Ques. Find the value of 44x – 5 = 162. (3 Marks)

Ans. 44x - 5 = 162

Now, we know that 16 can be expressed as a power of 4: 

44x - 5 = (42)2

44x - 5 = 44

4x – 5 = 4

4x = 9

X = 9/4

Ques. Find the value of 2-3 (2 Marks)

Ans. Given that 2-3

Since the power is in negative, so 

1/23

1/8

Ques. Simplify -45 x -4-10 (2 Marks)

Ans. Given, -45 x -4-10

= -45-10= -4-5 = 1/-45

= -1/1024

Ques. Simplify: 1/8 x 3-3 (2 Marks)

Ans. Given, 1/8 x 3-3

Ans. 1/23 x 3-3

= 2-3 x 3-3

= 6-3

=1/63

= 1/216

Ques. Simplify (-4)-3 x 5-3 x (-5)-3 (2 Marks)

Ans. Given that (-4)-3 x 5-3 x (-5)-3

[-4 x 5 x -5]-3

Now, (100)-3 = 1/1003

= 1/1000000

Ques. Simplify and write the answer: (25 / 28)5 x 2-5 (2 Marks)

Ans. Given that (25 / 28)5 x 2-5

(25-8)5 x 2-5

2-15 x 2-5

2-20

1/220

Ques. What will be the value of (2/3)-2? (2 Marks)

Ans. We are given that, 

(2/3)-2

= 2-2/3-2

= 32/22

9/4

Ques. Find m so that -3m+1 x -35 = -37 (2 Marks)

Ans. Here, the equation is given as 

= -3m+1+5= -37

So now, the bases will be cancelled, 

M+1+5 = 7

M= 7-6= 1

Ques. Express 4-3 as a power with base 2. (2 Marks)

Ans. We have 4 = 2x2 = 22

Therefore, 4-3 = (2x2)-3 = (22)-3

= 22(-3) = 2-6

= 1/26

Ques. What will be the value of 25/2-6? (2 Marks)

Ans. We are given that, 

= 25-(-6)

= 211

=2048

CBSE X Related Questions

  • 1.
    A bag contains 25 balls. Some of them are yellow and others are green. One ball is drawn at random. If probability of getting a green ball is $3/5$, then find the number of yellow balls.


      • 2.
        PQ and PR are two tangents to a circle with centre O and radius 5 cm. AB is another tangent to the circle at C which lies on OP. If OP = 13 cm, then find the length AB and PA.


          • 3.
            Prove that $14 - 2\sqrt{3}$ is an irrational number, given that $\sqrt{3}$ is irrational.


              • 4.
                The dimensions of a window are $156\text{ cm} \times 216\text{ cm}$. Arjun wants to put grill on the window creating complete squares of maximum size. Determine the side length of the square and hence find the number of squares formed.


                  • 5.
                    A chord of a circle, of radius 14 cm, subtends an angle of $60^\circ$ at the centre. Find the area of the smaller sector and perimeter of the smaller segment.


                      • 6.
                        Assertion (A) : The system of linear equations $3x - 5y + 7 = 0$ and $-6x + 10y + 14 = 0$ is inconsistent.
                        Reason (R) : When two linear equations don't have unique solution, they always represent parallel lines.

                          • Both Assertion (A) and Reason (R) are true and Reason (R) is the correct explanation of the Assertion (A).
                          • Both Assertion (A) and Reason (R) are true, but Reason (R) is not the correct explanation of the Assertion (A).
                          • Assertion (A) is true, but Reason (R) is false.
                          • Assertion (A) is false, but Reason (R) is true.

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