If sinsin−115+cos−1x=1 then x is equal to
1
0
4/5
1/5
We have, sinsin−115+cos−1x=1 ⇒sin−115+cos−1x=sin−11⇒sin−115+cos−1x=π2⇒cos−1x=π2−sin−115⇒cos−1x=cos−115 ∴x=15