If `tan alpjha=2`, then he value `("co s ec"^(2) alpha-sec^(2) alpha)/("co s ec"^(2)alpha+sec^(2) alpha)is `
If `tan alpjha=2`, then he value
`("co s ec"^(2) alpha-sec^(2) alpha)/("co s ec"^(2)alpha+sec^(2) alpha)is `
A. `-(15)/(9)`
B. `(3)/(5)`
C. `(3)/(5)`
D. `(17)/(5)`
4 views
1 Answers
Correct Answer - c
`tan alpha=2` (given)
`=(tan^(2)alpha-sec^(2)alpha)/(co s ec^(2)alph+sec^(2)alpha)`
(Divide by `co s ec^(2)alpha` "both in N and D")
`=(1-tan^(2)alpha)/(1+tan^(2)alpha)`
`=(1-(2)^(2))/(1+(2)^(2))`
`(1-(2)^(2))/(1+(2)^(2))`
` =-(3)/(5)`
4 views
Answered