定义在R上的函数f(x)满足f(x+y)=f(x)+f(y)+2xy(x,y∈R),f(1)=2,则f(-3)=________.
已知f(α)=,则f的值为________.
已知α为锐角,且2tan(π-α)-3cos+5=0,tan(π+α)+6sin(π+β)=1,则sin α的值是______.
已知cos=,且|φ|<,则tan φ=______.
若 tan α=3,则 sin2 α-2 sin αcos α+3 cos2 α=______.
若sin=,则cos=________.