( \frac { \operatorname { sin } 35 ^ { \circ } } { \operatorname { cos

1.	( \frac { \operatorname { sin } 35 ^ { \circ } } { \operatorname { cos } 55 ^ { \circ } } ) ^ { 2 } + ( \frac { \operatorname { cos } 55 ^ { \circ } } { \operatorname { sin } 35 ^ { \circ } } ) - 2 \operatorname { cos } 60 ^ { \circ }
Answer» sin35=sin(90-55)=cos55cos55=cos(90-35)=sin35cos60=1/2so (cos55/cos55)^2+(sin35/sin35)^2-2(1/2)=1+1-1=1 Thanks

( \frac { \operatorname { sin } 35 ^ { \circ } } { \operatorname { cos } 55 ^ { \circ } } ) ^ { 2 } + ( \frac { \operatorname { cos } 55 ^ { \circ } } { \operatorname { sin } 35 ^ { \circ } } ) - 2 \operatorname { cos } 60 ^ { \circ }

Answer»

sin35=sin(90-55)=cos55cos55=cos(90-35)=sin35cos60=1/2so (cos55/cos55)^2+(sin35/sin35)^2-2(1/2)=1+1-1=1

Thanks