a.c= (sinπ/3,cosπ/3).(-1,0)
cosz= -sinπ/3
z = 5π/6
f(x) = αsinx(sinx+cosx)
f'(x) = α[cosx(sinx+cosx)+sinx(cosx-sinx)]=0
x=3π/8
f(3π/8)=1/2
α = 1/[2sin3π/8(sin3π/8+cos3π/8)]
a.c= (sinπ/3,cosπ/3).(-1,0)
cosz= -sinπ/3
z = 5π/6
f(x) = αsinx(sinx+cosx)
f'(x) = α[cosx(sinx+cosx)+sinx(cosx-sinx)]=0
x=3π/8
f(3π/8)=1/2
α = 1/[2sin3π/8(sin3π/8+cos3π/8)]