If $3(sec^2\theta + tan^2 \theta)= 5, 0° < \theta < 90°, $ then the value of cosec θ is :
Answer & explanation
Correct answer: option 3
3( sec²θ + tan²θ ) = 5 ----(1)
We know,
sec²θ - tan²θ = 1
Multiply this equation with 3 and add into equation 1.
6 sec²θ = 8
secθ = \(\frac{2}{√3}\)
{ we know, sec30º = \(\frac{2}{√3}\) }
so, θ = 30º
Now,
cosecθ
= cosec 30º
= 2