To find the value of \( \sin^2 30^\circ + \cos^2 60^\circ \), we first calculate each trigonometric function:
\( \sin 30^\circ = \frac{1}{2} \) and \( \cos 60^\circ = \frac{1}{2} \).
Thus, \( \sin^2 30^\circ = \left(\frac{1}{2}\right)^2 = \frac{1}{4} \) and \( \cos^2 60^\circ = \left(\frac{1}{2}\right)^2 = \frac{1}{4} \).
Adding these values gives \( \sin^2 30^\circ + \cos^2 60^\circ = \frac{1}{4} + \frac{1}{4} = \frac{1}{2} \).
Therefore, the correct answer is \( \frac{1}{2} \).
The value of \(\dfrac{\sqrt{3}\cosec 20^\circ - \sec 20^\circ}{\cos 20^\circ \cos 40^\circ \cos 60^\circ \cos 80^\circ}\) is equal to
If $\cot x=\dfrac{5}{12}$ for some $x\in(\pi,\tfrac{3\pi}{2})$, then \[ \sin 7x\left(\cos \frac{13x}{2}+\sin \frac{13x}{2}\right) +\cos 7x\left(\cos \frac{13x}{2}-\sin \frac{13x}{2}\right) \] is equal to
If \[ \frac{\cos^2 48^\circ - \sin^2 12^\circ}{\sin^2 24^\circ - \sin^2 6^\circ} = \frac{\alpha + \beta\sqrt{5}}{2}, \] where \( \alpha, \beta \in \mathbb{N} \), then the value of \( \alpha + \beta \) is ___________.