Trigonometry Quiz 6

If tan2A = cot (A – 18°), where 2A is an acute angle, then A =

If x = a $cosec\theta$ and y = b $cot\theta$, then $b^2x^2 – a^2y^2 =$

tan 30°, tan 45°, tan 60° are in

$cos^4 \theta-sin^4\theta=$

$sin 0^\circ . tan 60^\circ. cos 30^\circ. cosec 45^\circ =$

If sin(A + B) = $\frac{1}{\sqrt2}$ and cos (A – B) = $\frac{1}{\sqrt2}$ then $\angle B$ =

If sin$\theta$ + cos$\theta$  = $\sqrt2$ then $\theta$  =

$\frac{1-tan^2 30^\circ}{1+tan^2 30^\circ} = .........$

$cos^4 \theta-sin^4\theta=$

If x = cos $\theta$  + sin $\theta$ and y = cos $\theta$ – sin $\theta$, then $x^2$ + $y^2$ =