Trigonometric Functions and Ratios

This video tutorial covers the calculation of sine, cosine, and tangent of angles in the coordinate plane using right triangle geometry. It reviews the Pythagorean theorem and the SOHCAHTOA mnemonic, explaining how to find the sine and cosine of 90 degrees using the coordinates of a point on the terminal ray. The tutorial also includes an example problem and highlights common mistakes students make when switching x and y axes.

What is the longest side of a right triangle called?

• Base

• Hypotenuse

• Opposite

• Adjacent

Which acronym helps remember the trigonometric ratios?

• ABCD

• PQR

• XYZ

• SOHCAHTOA

Why can't SOHCAHTOA be used to find the sine of a 90-degree angle?

• It only works for acute angles

• It requires a calculator

• It is only for obtuse angles

• It is outdated

In the coordinate plane method, what does 'r' represent?

• The hypotenuse

• The origin

• The y-coordinate

• The x-coordinate

What is the sine of 90 degrees using the coordinate plane method?

• Undefined

• 0

• 1

• 0.5

What is the cosine of 90 degrees?

• 1

• 0.5

• 0

• Undefined

If a terminal ray passes through the point (3, 4), what is the hypotenuse?

• 3

• 4

• 5

• 6

What is the sine of an angle if the terminal ray passes through (3, 4)?

• 5/4

• 5/3

• 4/5

• 3/5

What is the cosine of an angle if the terminal ray passes through (3, 4)?

• 3/5

• 4/5

• 5/3

• 5/4

What common mistake do students make when using the coordinate plane method?

• Switching x and y axes

• Forgetting the hypotenuse

• Using the wrong formula

• Ignoring the origin