If $cosec~ \theta+\cot \theta=p$, then the value of $\frac{p^2-1}{p^2+1}$ is:
Answer & explanation
Correct answer: option 1
We are given that :-
cosec θ + cot θ = p -----(1)
{ we know, cosec² θ - cot² θ = 1
So, cosec θ - cot θ = \(\frac{1 }{cosec θ + cot θ}\) }
So, cosec θ - cot θ = \(\frac{1 }{p}\) ----(2)
On adding equation 1 and 2 .
2 cosec θ = p + \(\frac{1 }{p}\)
2 cosec θ = \(\frac{ P² + 1 }{p}\) ------(3)
On subtracting equation 1 from 2 .
2 cot θ = p - \(\frac{1 }{p}\)
2 cot θ = \(\frac{ P² -1 }{p}\) ----(4)
Subtracting euation 4 by equation 3
cos θ = \(\frac{ P² -1 }{p}\) × \(\frac{ P }{P² +1}\)
cos θ = \(\frac{ P² -1 }{p²+1}\)
So, Ans :- cosθ