All Precalculus Resources
Example Question #21 : Trigonometric Functions
Which of the following statements is false?
Of the six trigonometric functions, four are odd, meaning . These four are:
- sin x
- tan x
- cot x
- csc x
That leaves two functions which are even, which means that . These are:
- cos x
- sec x
Of the aforementioned, only is incorrect, since secant is an even function, which implies that
Example Question #22 : Trigonometric Functions
Find the value of .
Rewrite by odd and even identities.
Use the difference identity of sine, and choose the special angles 45 and 30, since their difference equals to 15.
Example Question #23 : Trigonometric Functions
Write the even and odd identities for sine and cosine.
Rewrite the expression and evaluate.
Example Question #1 : Use Odd Even Identities
In order to simplify , rewrite the expression after applying the rule of odd-even identities for the secant function.