Multiple Choice QuestionsIf x sin3θ + y cos3θ = sin θ cos θ ≠ 0
and x sin θ - y cos θ = 0, then the value of (x2 + y2) is
sin θ - cos θ
sin θ + cos θ
0
1
D.
1
Given, x sin3θ + y cos3θ = sinθ cos θ ...(i)
and x sin θ - y cos θ = 0
or x sin θ = y cos θ ...(ii)
Put the value of eq (ii) in eq (i),
y cos θ . sin2θ + y cos3θ = sin θ cos θ
y cos θ (sin2 θ + cos2θ) = sin θ cos θ
⟹ y = sin θ
Put the value of y = sin θ in eq (ii), we get
x = cos θ
∴ x2 + y2 = sin2 θ + cos2 θ = 1
and 
, then the value of x2y2 (x2 + y2 + 3) is
and 
then the value of x2 + 4y2 is
then the value of cos (75° - θ) is
and 
then the value of 
is
Switch
then the value of 
is
