Perhaps the most famous and useful equation in all of mathematics is the Pythagorean Theorem. The following rules provide shortcuts for dealing with negative input. The quotient identities are useful for re-expressing the trig functions in terms of sin and/or cos. Below is a list of what I would consider the essential identities. The Essential Trigonometric Identitiesįortunately, you do not have to remember absolutely every identity from Trig class. The Unit Circle, which displays cosine and sine values of common angles. Based on the unit circle diagram, you know: Each point ( x, y) on the circle gives the value of cosine and sine of the corresponding angle.įor example, look for the angle 2π/3 (radians). The Unit Circleįirst of all, you should be familiar with the Unit Circle. Specifically, these identities seem to come up more often when working out integrals, especially on the no-calculator sections of the test. Moreover, the trigonometric identities also help when working out limits, derivatives and integrals of trig functions. Trigonometry is useful when setting up problems involving right triangles. What are trigonometric identities doing on a Calculus exam? I’m glad you asked! Because mathematics tends to build upon previous results, you can expect to use all of your prior math knowledge when working on calculus problems.
