`sintheta=0.7`, then `costheta,0 le theta lt 90^(@)` is `sintheta=0.7` है तो `costheta=? (0 le theta lt 90^(@)` है )

Options

A. `0.3`
B. `sqrt(0.49)`
C. `sqrt(0.51)`
D. `sqrt(0.9)`

Answer

c

Explanation

`sin theta=0.7`
`sin^(2)theta+cos^(2)theta=1`
`(0.7)^(2)+cos^(2)theta=1`
`0.49+cos^(2)theta=1`
`cos^(2)theta=1-0.49`
`cos theta=sqrt(0.51)`