1987 年

Let $n$ be a positive integer. Which of the following number is/are odd? I. $2^{2n+1}$ II. $2^n+1$ III. $3(2^n)$

In the figure, $AD=p$, $CD=q$ and $\angle B=90^\circ$, $BC=$

In the figure, $O$ is the centre of the circle. If $AB=12$ and $AC=13$, then $\cos\theta=$

In the figure, $ABCD$ is a rectangle inclined at an angle of $30^\circ$ to the horizontal plane $ABEF$. $\angle CBD=60^\circ$. Let $\theta$ be the inclination of $BD$ to the horizontal plane. $\sin\theta=$

How many different values of $x$ between $0^\circ$ and $360^\circ$ will satisfy the equation $(\sin x+1)(2\sin x+1)=0$?

If $0^\circ\le x<360^\circ$, the number of points of intersection of the graph of $y=\sin x$ and $y=1+\cos x$ is

In $\triangle ABC$, if $AB:BC:CA=4:5:6$, then $\cos A=$

In the figure, $O$ is the centre of the circle of radius 4. The area of the shaded region is

In the figure, $C$ is the centre of the circle. $ABCD$ is a straight line. $AQR$ touches the circle at $Q$. If $\angle DAR=20^\circ$, then $\angle DQR=$

In the figure, $DE\parallel BC$ and $AB\parallel EF$. If $AE:EC=1:2$, then area of $\triangle ADE$ : area of parallelogram $BFED=$