Precalculus : Use Odd-Even Identities

Example Questions

Example Question #1 : Fundamental Trigonometric Identities

Which of the following statements is false?      Explanation:

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 #1 : Use Odd Even Identities

Find the value of .      Explanation:

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 #1 : Use Odd Even Identities

Simplify:       Explanation:

Write the even and odd identities for sine and cosine.  Rewrite the expression and evaluate. Example Question #4 : Fundamental Trigonometric Identities

Simplify:       Explanation:

In order to simplify , rewrite the expression after applying the rule of odd-even identities for the secant function.  All Precalculus Resources 