If sin θ + cosec θ = 7, then what is the value of $ sin^3θ + cosec ^3 θ $ ?
Answer & explanation
Correct answer: option 3
sin θ + cosec θ = 7
sin θ + \(\frac{1}{sin θ}\)= 7
Using ,
{ if x + \(\frac{1}{x}\) = a , then x³ + \(\frac{1}{x³ }\) = a³ - 3a }
So,
sin³ θ + \(\frac{1}{sin³ θ}\) = 7³ - 21
= 322