Trig Substitution with Radicals

 In the first example, what is x equal to?

• 4 tan θ

• 4 cos θ

•  4 sec θ

• 4 csc θ

What will be the result of substituting x = 4 sec θ into √(x² - 16)?

• √(16 sec² θ - 16)

• √(16 tan² θ - 16)

• √(16 cos² θ - 16)

• √(16 sin² θ - 16)

 Which trigonometric identity can be used to substituted for sec² θ - 1?

• sin² θ + cos² θ = 1

•  tan² θ + 1 = sec² θ

• csc² θ - 1 = cot² θ

•  sec² θ - tan² θ = 1

What will be the result of substituting x = 5 cot θ into √(x² + 25)?

• √(25 cot² θ + 25)

• √(25 tan² θ + 25)

•  √(25 sec² θ + 25)

• √(25 csc² θ + 25)

What will be the final result of simplifying √(x² + 25) when x = 5 cot θ?

•  5 sin θ

•  5 cos θ

• 5 tan θ

• 5 csc θ