Lesson 7C: Laws of Logarithms

Logarithms are an important tool for finding an unknown exponent in any exponential equation such as f(t) = abt. As you have seen, these equations are useful for modelling real world situations such as population growth or decay.

Compound interest, the intensity of light as it passes through water or glass, the stopping distances at various speeds, and the time a substance takes to cool are also examples of problems that can be modelled by exponential functions.

In Lesson 6C, you solved problems of this type by using the graph of an exponential function. In this lesson, you will see how, by using logarithms, solutions can be determined algebraically.

In this Training Camp, you will learn to simplify logarithmic expressions and solve equations using logarithms.

By the end of this lesson, you should be able to

	determine an equivalent expression for a logarithmic expression by applying the laws of logarithms
	determine the solution to an exponential equation in which bases are not powers of one another