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Basic Definitions of Exponentials and Logarithms
- The function e^x is called the exponential function. It’s so named because the variable, x, is the exponent.
- The function ln x is called the natural logarithm function. The term “natural” refers to the function’s base, which is the constant e.
Properties of Exponential Functions
- e^0 = 1: Any exponential function raised to the power 0 gives 1.
- e^1 = e: Any exponential function raised to the power 1 gives itself.
- e^(x + y) = e^x * e^y: This property is used when you need to simplify expressions with the same base and different powers.
Properties of Natural Logarithms
- ln 1 = 0: The logarithm of 1 to any base equals 0.
- ln e = 1: The natural log of e equals 1.
- ln(e^x) = x: This property is the fundamental property of logarithms and is crucial to solving exponential equations using natural logs.
Creating Equations and Solving Problems: Exponential Functions
- To formulate an exponential equation, remember that the basic form is y = ab^x where a is the initial amount, b is the growth factor and x is the exponent.
- Exponential functions can be used to model many real-world scenarios, including population growth, radioactive decay, and compound interest.
Creating Equations and Solving Problems: Logarithmic Functions
- The logarithmic form of an exponential equation is log_b(a) = x, where b is the base, a is the number you’re taking the log of, and x is the power the base must be raised to achieve a.
- Logarithmic functions can be applied to solve various real-world problems such as calculating pH levels, decibel levels, and Richter scale measurements.