Purchase Solution

Trigonometric Identities

Not what you're looking for?

Ask Custom Question

What are different kinds of trig identities?


1. If sin x = -1/3, what is cosx?

2. Simplify the expression (sinx + cosx)^2 + (sinx - cosx)^2

3. Verify the identity cotx - tanx = (csc2x - sec2x)/sinxcosx

Purchase this Solution

Solution Summary

This posting lists trigonometric identities and gives examples of different types of problems that make use of them.

Solution Preview


Pythagorean Identities

1. sin2x + cos2x = 1
2. tan2x + 1 = sec2x
3. 1 + cot2x = csc2x

Reciprocal Identities

1. cscx = 1/sinx
2. secx = 1/cosx
3. cotx = 1/tanx

The Tangent and Cotangent Identities

1. tanx = sinx/cosx
2. cotx = cosx/sinx

Identities for Negatives

1. sin(-x) = -sinx (the sine function is an odd function)
2. cos(-x) = cosx (the cosine function is an even ...

Purchase this Solution

Free BrainMass Quizzes
Multiplying Complex Numbers

This is a short quiz to check your understanding of multiplication of complex numbers in rectangular form.

Geometry - Real Life Application Problems

Understanding of how geometry applies to in real-world contexts

Know Your Linear Equations

Each question is a choice-summary multiple choice question that will present you with a linear equation and then make 4 statements about that equation. You must determine which of the 4 statements are true (if any) in regards to the equation.

Solving quadratic inequalities

This quiz test you on how well you are familiar with solving quadratic inequalities.

Exponential Expressions

In this quiz, you will have a chance to practice basic terminology of exponential expressions and how to evaluate them.