Pre Calc unit 3 how to use cosine to find the missing side of a triangle

The video tutorial explains how to use the cosine function in trigonometry to solve for X. It begins with an introduction to the cosine of 59 degrees, followed by a step-by-step guide to solving for X by multiplying both sides by 5. The instructor demonstrates the calculation and provides an approximate result. Finally, the video addresses potential errors and troubleshooting tips for students who may not get the correct answer.

What is the cosine of 59 degrees used to represent in a right triangle?

• Adjacent over hypotenuse

• Opposite over hypotenuse

• Hypotenuse over adjacent

• Opposite over adjacent

What operation is performed to solve for X in the equation X = 5 * cos(59°)?

• Subtract 5

• Divide by 5

• Add 5

• Multiply by 5

What is the approximate value of X when calculated as 5 times the cosine of 59 degrees?

• 1.575

• 3.575

• 2.575

• 4.575

Why is it important to check the mode of the calculator before calculating cosine?

• To ensure it is in radian mode

• To ensure it is in degree mode

• To ensure it is in scientific mode

• To ensure it is in standard mode

What should you do if your calculated result does not match the expected value?

• Ignore the discrepancy

• Use a different calculator

• Change the angle to radians

• Recheck the mode of the calculator