Question

$\sin \theta +{\sin }^2\theta -{\sin }^3\theta =1when\theta =?$

Answer 1

Solution: Correct equation is given as

$\Rightarrow \sin \theta +{\sin }^2\theta -{\sin }^3\theta =1$

$\Rightarrow \sin \theta -{\sin }^3\theta =1-{\sin }^2\theta$

when know ${\cos }^2\theta +{\sin }^2\theta =1$

$\Rightarrow \sin \theta (1-{\sin }^2\theta )={\cos }^2\theta$

$\Rightarrow \sin \theta \times {\cos }^2\theta ={\cos }^2\theta$

$\Rightarrow \sin \theta =1$

$\Rightarrow \theta =n\frac{\pi }{2}$ Ans where $n\in z$