If `co s ec theta-cot theta=(7)/(2)` the value of co s ec? (यदि `co s ec theta-cot theta=(7)/(2)` है तो का मान है )

Options

A. `(47)/(28)`
B. `(51)/(28)`
C. `(53)/(28)`
D. `(49)/(28)`

Answer

c

Explanation

`co s ec theta-cottheta=1`
`rArr[ coec theta-cot theta][co s ec theta+cot theta)=1`
`rArr(co s ec theta+cot theta)=(1)/((co s ectheta-cottheta))`
`rArr co s ec theta+cot theta=(2)/(7)` ..........(ii)
Adding both equation.
`rArr 2co s ectheta=(7)/(2)+(2)/(7)rArr`
`(49xx4)/(14)=(53)/(14)`
`rArrco s ec theta=(83)/(28)`