1.

if `theta=60^(@)`, then `(1)/(2)sqrt(1+sintheta)+(1)/(2)sqrt(1-sintheta)` is equal toA. `cot((theta)/(2))`B. `sec((theta)/(2))`C. `sin((theta)/(2))`D. `cos((theta)/(2))`

Answer» Correct Answer - d
` theta=60^(@)`
`rArr(1)/(2)sqrt(1+sintheta)+(1)/(2)sqrt(1+60^(@))+(1)/(2)sqrt(1-sin60^(@))`
`rArr(1)/(2)sqrt(1+(sqrt(3)/(2)))+(1)/(2)sqrt(1-(sqrt(3)/(2)))`
`rArr(1)/(2sqrt(2))(sqrt(2+sqrt(3))+sqrt(2-sqrt(3)))`
`rArr(1)/(4)(sqrt((sqrt(3)+1)^(2) ) +sqrt((sqrt(3)-1)^(2)))`
`rArr(1)/(4)(sqrt(3)+1+sqrt(3)+1)`
`rArr2sqrt(3)/(4)=sqrt(3)/(2)=cos30^(@)=(theta)/(2)`


Discussion

No Comment Found

Related InterviewSolutions