Solveeit Logo

Question

Question: If \(\sin^{2}\theta + \sin\theta - 2 = 0 \Rightarrow (\sin\theta - 1)(\sin\theta + 2) = 0\), then th...

If sin2θ+sinθ2=0(sinθ1)(sinθ+2)=0\sin^{2}\theta + \sin\theta - 2 = 0 \Rightarrow (\sin\theta - 1)(\sin\theta + 2) = 0, then the general value of \Rightarrowis.

A

sinθ2\sin\theta \neq - 2

B

sinθ=1=sinπ/2\therefore\sin\theta = 1 = \sin\pi/2

C

\Rightarrow

D

θ=nπ+(1)nπ2\theta = n\pi + ( - 1)^{n}\frac{\pi}{2}

Answer

sinθ2\sin\theta \neq - 2

Explanation

Solution

tanmθ=tannθ\tan m\theta = \tan n\theta

mθ=pπ+nθθ=pπ(mn)\Rightarrow m\theta = p\pi + n\theta \Rightarrow \theta = \frac{p\pi}{(m - n)}

\Rightarrow πmn\frac{\pi}{m - n}

tanθ2secθ=3sinθ3cosθ=2\tan\theta - \sqrt{2}\sec\theta = \sqrt{3} \Rightarrow \sin\theta - \sqrt{3}\cos\theta = \sqrt{2} \Rightarrow or sin(θπ3)=sinπ4θ=nπ+(1)nπ4+π3\sin\left( \theta - \frac{\pi}{3} \right) = \sin\frac{\pi}{4} \Rightarrow \theta = n\pi + ( - 1)^{n}\frac{\pi}{4} + \frac{\pi}{3}.