cos(pai/4+a)+sin(pai/4+a) =cos(π/4+a)+sin(π/4+a) = cosπ/4•cos a -sinπ/4•sin a+ sinπ/4•cos a+cosπ/4•sin a=√2/2•cos a -√2/2•sin a+ √2/2•cos a+√2/2R...