${\sin ^2}\frac{\pi }{8} + {\sin ^2}\frac{{3\pi }}{8} + {\sin ^2}\frac{{5\pi }}{8} + {\sin ^2}\frac{{7\pi }}{8} = $
${\sin ^2}\frac{\pi }{8} + {\sin ^2}\frac{{3\pi }}{8} + {\sin ^2}\frac{{5\pi }}{8} + {\sin ^2}\frac{{7\pi }}{8} = $
- A
$1$
- B
$-1$
- C
$0$
- D
$2$
Similar Questions
$(sinx + cosecx)^2 + (cosx + secx)^2 - ( tanx + cotx)^2$ =
$(sinx + cosecx)^2 + (cosx + secx)^2 - ( tanx + cotx)^2$ =
$\left( {1 + \cos \frac{\pi }{8}} \right)\,\left( {1 + \cos \frac{{3\pi }}{8}} \right)\,\left( {1 + \cos \frac{{5\pi }}{8}} \right)\,\left( {1 + \cos \frac{{7\pi }}{8}} \right) = $
$\left( {1 + \cos \frac{\pi }{8}} \right)\,\left( {1 + \cos \frac{{3\pi }}{8}} \right)\,\left( {1 + \cos \frac{{5\pi }}{8}} \right)\,\left( {1 + \cos \frac{{7\pi }}{8}} \right) = $
- [IIT 1984]
જો $\sin \left( {x + \frac{{4\pi }}{9}} \right) = a;\,$ $\frac{\pi }{9}\, < \,x\, < \,\frac{\pi }{3},$ થાય તો $\cos \left( {x + \frac{{7\pi }}{9}} \right)$ =
જો $\sin \left( {x + \frac{{4\pi }}{9}} \right) = a;\,$ $\frac{\pi }{9}\, < \,x\, < \,\frac{\pi }{3},$ થાય તો $\cos \left( {x + \frac{{7\pi }}{9}} \right)$ =
જો $x + y = 3 - cos4\theta$ અને $x - y = 4 \,sin2\theta$ હોય તો
જો $x + y = 3 - cos4\theta$ અને $x - y = 4 \,sin2\theta$ હોય તો
${\rm{cosec }}A - 2\cot 2A\cos A = $
${\rm{cosec }}A - 2\cot 2A\cos A = $