Cofunction Identities and Angles

The video tutorial covers cofunction identities in trigonometry, starting with a review of triangle angle sums. It explains the concept of cofunction identities, where two trigonometric functions are equal when their angles are complementary. The tutorial provides examples using both degrees and radians, demonstrating how to express one trigonometric function in terms of its cofunction. The video also includes verification of these identities using a calculator and the unit circle.

What is the sum of the interior angles of any triangle?

• 90 degrees

• 180 degrees

• 270 degrees

• 360 degrees

Which of the following is true for cofunction identities?

• Cosine of an angle equals the secant of its complement

• Tangent of an angle equals the sine of its complement

• Sine of an angle equals the cosine of its complement

• Sine of an angle equals the tangent of its complement

In a right triangle, if angle A is 50 degrees, what is angle B?

• 60 degrees

• 50 degrees

• 40 degrees

• 30 degrees

What is the cofunction of sine 18 degrees?

• Cosine 72 degrees

• Cosecant 72 degrees

• Tangent 72 degrees

• Secant 72 degrees

If tangent 65 degrees equals cotangent of angle B, what is angle B?

• 35 degrees

• 45 degrees

• 25 degrees

• 15 degrees

What is the cofunction of cosecant 84 degrees?

• Sine 6 degrees

• Cosine 6 degrees

• Tangent 6 degrees

• Secant 6 degrees

What is the cofunction of cosine pi/4 radians?

• Sine pi/4

• Sine pi/3

• Sine pi/6

• Sine pi/2

If cotangent pi/3 equals tangent of angle B, what is angle B in radians?

• pi/2

• pi/4

• pi/6

• pi/3

What is the cofunction of secant pi/6 radians?

• Cosecant pi/3

• Cosecant pi/4

• Cosecant pi/2

• Cosecant pi/6

Which of the following is a correct cofunction identity in radians?

• Sine pi/6 = Cosine pi/3

• Secant pi/2 = Cosecant pi/2

• Cosine pi/3 = Sine pi/6

• Tangent pi/4 = Cotangent pi/4