α=max82sin3x⋅44cos3x
=max26sin3x⋅28cos3x
=max26sin3x+8cos3x
and β=min82sin3x⋅44cos3x=min26sin3x+8cos3x
Now range of 6sin3x+8cos3x
=[−62+82,+62+82]=[−10,10]
\alpha ={2}^{10}&\beta ={2}^{-10}
So, α1/5=22=4
⇒β1/5=2−2=41
The quadratic 8x2+bx+c=0,
sum of roots =8−b and product of roots =8c
∴c−b=8×[ (product of roots)+(sum of roots)]
=8×[4×41+4+41]=8×[421]=42