If tan θ + sin θ = A and tan θ - sin θ = B, then what is the value of $A^2 - B^2$ ?
Answer & explanation
Correct answer: option 3
A² - B²
= ( tan θ + sin θ )² - ( tan θ - sin θ )²
= tan² θ + sin² θ + 2 tan θ . sin θ - tan² θ - sin² θ + 2 tan θ . sin θ
= 4 tan θ . sin θ