The concepts introduced to students in algebra, trigonometry, and calculus are challenging so graphing calculators play a vital role by helping students absorb and retain complex mathematical concepts, including understanding cosine. David Joyce of Clark University provides a simple description of cosine as the sine of any given angle's complementary angle. The complementary angle equals the given angle subtracted from a right angle (i.e. 90 degrees). If a given angle is 30 degrees, then its complement is 60 degrees. So the cosine of 30 degrees is also the sine of 60 degrees. Calculating cosine on a graphing calculator is a straightforward process.
Things You'll Need
Graphing calculator
Pen
Paper
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Instructions
1
Write down the function whose cosine you would like to calculate. For example, use the function x² + 8. Convert it to calculator syntax, which would be x^2 + 8. Find the "cos" button on your calculator.
2
Use the calculator syntax to enter the cosine of the function in the calculator's graphing feature. Enter syntax such as: y=cos (x^2 + 8) or y1=cos (x^2 + 8).
3
Plot the graph of the cosine of the function. Observe the graph to note the corresponding point on the y-axis for the value of x whose cosine you need. If available, you can also use your calculators table feature to enter the specific value of x and its corresponding cosine, which is the value of y.