PLATE XKVn 



91. Siny sin ^5'= sinx sin J^3C. 



92. Sin^sin ^y=-sinx sill ^3C + .56. 



93. Sinysin^y=-sin xsin ^a:. 



94. Siny sin^y«-sin xsin ix-.44. 



95. Sinysin^y=-siii xsin ix + ^.. 



