Exponential function & Logarithmic function

Exponential function:

  • An exponential function is a mathematical function of the form f(x) = ab^x, where a and b are constants and b is the base of the exponential function.
  • Exponential functions exhibit exponential growth or decay, depending on whether b is greater than 1 or less than 1.
  • The exponential function is used in many areas of mathematics and science, including calculus, finance, physics, and biology.
  • The natural exponential function, denoted by e^x, is the exponential function with the base 'e'.
  • The exponential function is the inverse of the logarithmic function, and they can be used to solve equations involving logarithmic and exponential functions.

Logarithmic function:

  • A logarithmic function is a mathematical function of the form f(x) = logb(x), where b is the base of the logarithmic function and x is the argument.
  • Logarithmic functions are used to express the relationship between two quantities that are being multiplied or divided.
  • The natural logarithmic function, denoted by ln(x), is the logarithmic function with the base 'e'.
  • Logarithmic functions have several properties, including the product rule, quotient rule, power rule, and change of base rule.
  • Logarithmic functions are the inverse of exponential functions, and they can be used to solve equations involving exponential and logarithmic functions.

Important Formulas to Remember in these Exponential function & Logarithmic function


Exponential Function:

  • Definition: $$e^x = \sum_{n=0}^{\infty} \frac{x^n}{n!}$$

  • Properties:
    • $$e^{a+b} = e^ae^b$$


    • $$\frac{d}{dx}e^x = e^x$$

    • $$\int e^x\,dx = e^x + C$$

Logarithmic Function:

  • Definition: $$\ln x = \log_e x$$

  • Properties:
    • $$\ln 1 = 0$$

    • $$\ln e = 1$$

    • $$\ln(xy) = \ln x + \ln y$$

    • $$\ln\left(\frac{x}{y}\right) = \ln x - \ln y$$

    • $$\ln(x^c) = c\ln x$$

    • $$\ln e^x = x$$

    • $$\frac{d}{dx}\ln x = \frac{1}{x}$$

    • $$\int \frac{1}{x}\,dx = \ln |x| + C$$