" If "alpha in Q_(4)" and "sin(alpha)/(2)+cos(alpha)/(2)=(-1)/(2)" then "sin2 alpha=

If alpha in Q_(4) and "sin" (alpha)/(2) + "cos" (alpha)/(2) = (-1)/(2) "then sin 2" alpha =

If sin alpha/2 + cos alpha/2=1.4 , then: sin alpha cos alpha =

If (sin alpha)/(a)=(cos alpha)/(b), then a sin2 alpha+b cos2 alpha=

I : If (cos alpha )/(a)=(sin alpha )/(b) then a cos 2 alpha + b cos 2 alpha =a II : If (sin alpha )/(a) =(cos alpha )/(b) then a sin 2 alpha + b cos 2 alpha = a

sin alpha+sin2 alpha+sin4 alpha+sin5 alpha=4cos((alpha)/(2))cos(3(alpha)/(2))sin3 alpha

sin alpha+sin2 alpha+sin4 alpha+sin5 alpha=4cos((alpha)/(2))cos(3(alpha)/(2))sin3 alpha

cos^(4)alpha+sin^(4)alpha-6sin^(2)alpha cos^(2)alpha=

(1-2sin^(2)alpha)/(1+sin2 alpha)=(1-tan alpha)/(1+tan alpha)

(1-2sin^(2)alpha)/(1+sin2 alpha)=(1-tan alpha)/(1+tan alpha)