Trigonometric Functions and Quadrants

The video tutorial covers trigonometric concepts, focusing on the relationships between sine and cosine for angles A and B, and their behavior in different quadrants. It explains how to determine the positivity of trigonometric functions in various quadrants and evaluates specific trigonometric functions. The tutorial also explores the properties of isosceles triangles within the unit circle and discusses triangle similarity and scale factors.

Why are the sine and cosine of angles A and B considered opposites?

• Because they lie on the same straight line.

• Because they are in different quadrants.

• Because they are both positive.

• Because they have the same radius.

In which quadrant is the sine of an angle positive?

• Fourth quadrant

• First quadrant

• Third quadrant

• Second quadrant

If the tangent of an angle is positive, which quadrants could the angle be in?

• Second and third quadrants

• First and second quadrants

• First and third quadrants

• Third and fourth quadrants

What is the value of the tangent of 5π/4?

• 1

• Undefined

• -1

• 0

Why are the sine and cosine of angle A the same in an isosceles triangle in the unit circle?

• Because the triangle is equilateral.

• Because the opposite and adjacent sides are equal.

• Because the hypotenuse is equal to the opposite side.

• Because the radius is greater than one.

How does the scale factor affect the length of sides in similar triangles?

• It does not affect the length of sides.

• It multiplies the length of sides by the scale factor.

• It doubles the length of all sides.

• It triples the length of all sides.

In which quadrant are both the sine and cosine of an angle negative?

• Second quadrant

• Fourth quadrant

• First quadrant

• Third quadrant