1)

If the eccentricity of the hyperbola

x2-y2 cosec2α= 25 is 5    times the 

eccentricity of the elipse x2 cosec2α+y2=5 then α is equal to;


A) tan12

B) sin134

C) tan125

D) sin125

Answer:

Option A

Explanation:

Eccentrcity of x225+y225sin2α=1   is

1+sin2α

Eccentrcity of x25sin2α+y25=1     is

1sin2α

Given, 1+sin2α=51sin2α

⇒ sin2α=23

⇒ α=sin123=tan12