This video explains how to simplify a trigonometric expression by converting to sines and cosines.

# trigonometry

# Ex: Find a Bounded Area Using Circles and Squares

This video explains how to determine a bounded area from a diagram of circles and squares. The properties of right triangles, squares and circles are used.

# Find the Area of a Circle Bounded by Two Squares

This video explains how to determine the area of a circle bounded by two squares. The properties of right triangles, squares and circles are used.

# Vector Application Using Law of Sines: Find Direction Angle Needed to Fly Due North in Wind

This video explains how to use vectors and the law of sines to determine an angle a plane must fly in wind to fly due north.

# Vector App Using Law of Sines and Cosines: Find Angle Off Course and Velocity of a Plane in Wind

This video explains how to use vectors and the law of sines and the law of cosines to determine an angle a plane would be off course and the speed of a plane in wind.

# Ex: Find Length of a Support Wire on a Hill Using the Law of Cosines

This video explains how to use the law of cosines to determine the length of a guy wire of a tower on a hill using the law of cosines.

# Ex: Law of Cosine Application (Cable Car to Top of Mountain)

This video explains how to determine the length of a side of an obtuse triangle using right triangle trigonometry and the law of cosines.