{"id":9192,"date":"2017-02-24t12:04:54","date_gmt":"2017-02-24t20:04:54","guid":{"rendered":"\/\/www.catharsisit.com\/hs\/?p=9192"},"modified":"2017-02-24t12:04:54","modified_gmt":"2017-02-24t20:04:54","slug":"ap-calculus-review-functions-graphs","status":"publish","type":"post","link":"\/\/www.catharsisit.com\/hs\/ap\/ap-calculus-review-functions-graphs\/","title":{"rendered":"ap calculus review: functions and their graphs"},"content":{"rendered":"
at the heart of calculus is the concept of functions and their graphs. all of the main areas of calculus, including limits<\/em>, derivatives<\/em>, and integrals<\/em>, require a firm understanding of functions. in this review we will explore what you need to know about functions and their graphs in order to succeed on the ap calculus exams.<\/p>\n the main concepts concerning graphing and functions include:<\/p>\n let’s start with the basics. <\/p>\n by definition a function<\/strong> is just a rule that assigns to each input x<\/em> a well-defined output y<\/em>. we use the notation y<\/em> = f<\/em>(x<\/em>) to indicate that x<\/em> is the input, y<\/em> is the output, and f<\/em> is the name of the function.<\/p>\n in principle, the input and output could be anything: numbers, vectors, symbols, even other functions! typically in calculus the input and output are real numbers<\/a>.<\/p>\n generally a function in calculus is defined by an expression that shows how to calculate the output from any given input. for example, the squaring function f<\/em>(x<\/em>) = x<\/em>2<\/sup> has input x<\/em> and output y<\/em> = x<\/em>2<\/sup>. <\/p>\n evaluating a function on a given input is often called plugging in<\/em>. continuing with our example, f<\/em>(x<\/em>) = x<\/em>2<\/sup>, let’s see how to evaluate f<\/em> at various inputs.<\/p>\n the last example in the list illustrates a composition<\/strong> of two functions, f<\/em> and g<\/em>. understanding how compositions work helps you to make sense of the chain rule<\/a> for derivatives and the substitution rule for integrals.<\/p>\n the domain<\/strong> of a function f<\/em>(x<\/em>) is the set of all input values (x<\/em>-values) for the function. <\/p>\n unless further information is given, we look for the natural domain<\/strong>, which is the largest set of x<\/em>-values that makes sense for the function. <\/p>\n for example, the domain of f<\/em>(x<\/em>) = x<\/em>2<\/sup> is the set of all real numbers, or (-∞, ∞) in interval notation. any real number at all can serve as input for this function.<\/p>\n on the other hand, the domain of a rational function such as we find that x<\/em> = 5 and x<\/em> = -2 must be excluded. therefore the domain is: (-∞, -2) u (-2, 5) u (5, ∞).<\/p>\n the range<\/strong> of a function is the set of all output values (y<\/em>-values) for the function.<\/p>\n finding the range is quite a bit more challenging than finding domain in general. it helps to memorize the domains and ranges of simple functions first. <\/p>\n\n
functions and their graphs<\/h2>\n
evaluating functions<\/h3>\n
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domain<\/h3>\n
excludes any x<\/em>-values for which the denominator evaluates to zero. factoring the bottom in this example,<\/p>\n
<\/p>\n
range<\/h3>\n