To simplify the expression sin²(θ) / (1 – sin²(θ)), we start by recognizing a fundamental trigonometric identity. We know that:
1 – sin²(θ) = cos²(θ)
Using this identity, we can substitute cos²(θ) for 1 – sin²(θ) in the original expression:
sin²(θ) / (1 – sin²(θ)) = sin²(θ) / cos²(θ)
This expression can be rewritten using the definition of the tangent function, which states that:
tan(θ) = sin(θ) / cos(θ)
Therefore, we can further simplify:
sin²(θ) / cos²(θ) = (sin(θ) / cos(θ))² = tan²(θ)
So, the simplified form of the given expression is:
tan²(θ)