1.

If `sin theta=11/61`, ffind the value of `cos theta` using trigonometric identity.

Answer» `sin theta=11/61`………(Given)
`sin^(2) theta+cos^(2) theta=1`………(Identity)
`:.(11/61)^(2)+cos^(2) theta=1`
`:.cos^(2) theta=1-(11/61)^(2)`
`:.cos^(2) theta=1-121/3721`
`:.cos^(2) theta=(3721-121)/3721`
`:.cos^(2) theta=3600/3721`
`:.cos theta=60/61` .............(Taking square roots of bothh the sides)
`cos theta=60/61`


Discussion

No Comment Found