The set of all real values of \( \lambda \) for which the function \( f(x) \)\( =\left(1-\cos ^{2} x\right) \cdot(\lambd…

The set of all real values of \( \lambda \) for which the function \( f(x) \)\( =\left(1-\cos ^{2} x\right) \cdot(\lambda+\sin x), x \in\left(-\frac{\pi}{2}, \frac{\pi}{2}\right) \) has exactly one maxima and exactly one minima, is :

[JEE Main 2020, 6 Sep (Shift 2)]