Module 5: Trigonometry Applications and Identities

 

Try This 3

 

This photo shows an electrical outlet and the electrical plug that matches the outlet.

Photodisc/Adam Crowley/Thinkstock

In Canada, the electricity you commonly use from an outlet is an alternating current. This means the current moves back and forth to produce a voltage that cycles between positive and negative. The current makes 60 cycles per second.

 

The equation V = 170 cos (120πt) models the electrical current, where V is voltage and t is time in seconds.

  1. Determine the voltage at 0.61 s.
  2. Determine the times at which the voltage is equal to 100.

course folder Save your answers in your course folder.

 

Share 3

 

With a partner or group, discuss the following question based on your solutions to Try This 3.

 

How do your strategies for solving question 2 in Try This 3 compare?

 

course folder If required, save a record of your discussion in your course folder.