解析：∵│cosαsinβ│=√(1-sin^α)(1-cos^β)=√[1-(sin^α+cos^β)+(sinαcosβ)^2]=√[1-(sin^α+cos^β)+1/16]=√[17/16-(sin^α+cos^β)]≤√[17/16-2sinαcosβ]=√9/16=3/4∴-3/4≤cosαsinβ≤3/4...