The video tutorial explains how to express the sine of an angle, referred to as alpha, and explores the geometric and algebraic methods to find the cosine of alpha. It involves drawing a triangle, calculating the adjacent side, and simplifying expressions by rationalizing denominators.

What is the expression for sine of alpha in the given problem setup?

• X / sqrt(2)

• sqrt(X^2 + 4) / 2

• 2 / sqrt(X^2 + 4)

• 2X / (X^2 + 4)

What is the next step after setting up the triangle to find the cosine of alpha?

• Determine the opposite side

• Solve for the angle

• Find the adjacent side

• Calculate the hypotenuse

How do you find the adjacent side in the problem?

• By multiplying the opposite side by the hypotenuse

• By using the Pythagorean theorem

• By subtracting the opposite side from the hypotenuse

• By dividing the hypotenuse by the opposite side

What is the purpose of rationalizing the denominator in this context?

• To find a new hypotenuse

• To make the expression more complex

• To simplify the expression

• To change the angle

When should you consider rationalizing the denominator according to the tutorial?

• When the numerator is larger than the denominator

• When the expression is already simplified

• Whenever you see a fraction

• Only when explicitly instructed