If (a2 – b2) sin θ + 2abcosθ = a2 + b2, then tan θ
1). $\frac{{2{\rm{ab}}}}{{{{\rm{a}}^2} - {{\rm{b}}^2}}}$
2). $\frac{{{{\rm{a}}^2} - {{\rm{b}}^2}}}{{2{\rm{ab}}}}$
3). $\frac{{{\rm{ab}}}}{{{{\rm{a}}^2} - {{\rm{b}}^2}}}$
4). $\frac{{{{\rm{a}}^2} - {{\rm{b}}^2}}}{{{\rm{ab}}}}$
⇒ (a2 – b2) sin θ + 2abcos θ = a2 + b2
⇒ Divide both sides by (a2 + b2)
⇒ [(a2 - b2)/(a2 + b2)] sin θ + [2ab/(a2 + b2)] cos θ = 1
⇒ Sin θ = [(a2 - b2)/(a2 + b2)] ---- 1
⇒ cos θ = [2ab/(a2 + b2)] ---- 2
⇒ From equation 1 and 2
∴ tan θ = (a2 - b2)/2ab