Question

if y + 1/y = 2, then find the value of 16 ycube + 1/4 ycube

Answer 1

here ,

y + 1/2 = 2

y=2-1/2 =(4-1)/2 =3/2

now, 16y^3+1/4y^3

=16×(3/2)^3+1/4×(3/2)^3

=16×3/2×3/2×3/2+ 1/4× 3/2×3/2×3/2

=2×3×3×3 +27/32

=54 +27/32

=(1728+27)/32

=1755/32

=54.84375.