Students can visit Khan Academy to find online tutorials on various trigonometric topics, such as unit circles, graphing trigonometric functions and trigonometric identities. Online calculators, such as the trigonometric equation calculator on Symbolab and the right triangle calculator on the Carbide Depot website, are helpful for checking answers to problems.
Khan Academy features a basic trigonometry section where students can find explanations of many foundational topics they need to understand before moving on to performing more complex trigonometric calculations. Here, students can learn the meaning and application of SOHCAHTOA, a commonly referenced memory tool in trigonometry classes that helps students remember the nature of the sine, cosine and tangent functions. The first three letters, SOH, serve as a reminder that the sine of an angle in a right triangle is equal to the length of the triangle side opposite the angle divided by the length of the hypotenuse. CAH indicates that the cosine of an angle equals the adjacent side divided by the hypotenuse, and TOA reminds students the tangent of an angle equals the opposite side divided by the adjacent side.
Once students review the tutorials on the sine, cosine and tangent functions, they can move on to reviewing information about the three reciprocal trigonometric functions. These include secant, cosecant and cotangent.