Correct Answer - Option 1 : A
Given:
Sin θ tan θ - sec θ
Concept used:
sin2 θ + cos2 θ = 1
Calculation:
tan θ = sin θ/cos θ
sec θ = 1/cos θ
sin θ tan θ - sec θ = sin θ × (sin θ /cos θ ) - (1/cos θ )
sin θ tan θ - sec θ = sin2 θ /cos θ - 1/cos θ = (sin2 θ - 1)/cos θ
sin θ tan θ - sec θ = -(1 - sin2 θ)/cos θ = -cos2 θ/cos θ
sin θ tan θ - sec θ = -cos θ
∴ The value of the expression is -cos θ.