sinA=√5/5 ∴cosA=2√5/5 sinB=√10/10 ∴cosB=3√10/10
∴sin(A+B)=sinAcosB+cosAsinB=√2/2 A,B均为锐角,A+B=45°或135°
a-b=√2-1,sinA*2R-sinB*2R=√2-1 2R=√10 a/sinA=b/sinB=c/sinC=√10
a=√2 b=1 c=√5
sinA=√5/5 ∴cosA=2√5/5 sinB=√10/10 ∴cosB=3√10/10
∴sin(A+B)=sinAcosB+cosAsinB=√2/2 A,B均为锐角,A+B=45°或135°
a-b=√2-1,sinA*2R-sinB*2R=√2-1 2R=√10 a/sinA=b/sinB=c/sinC=√10
a=√2 b=1 c=√5