Question

If $O$ is the origin and the line $OP$ of length $r$ makes an angle $\alpha$ with $x$-axis lies in a coordinate plane containing $x$-axis, then the coordinates of $P$ are

• A. $(r\cos \alpha ,o,r\sin \alpha )$
• B. $(r\cos \alpha ,r\sin \alpha ,o)$
• C. $(o,r\cos \alpha ,r\sin \alpha )$
• D. $(r\sin \alpha ,o,r\cos \alpha )$

Answer 1

Answer: (A), (B)

The correct options are
A $(r\cos \alpha ,o,r\sin \alpha )$
B $(r\cos \alpha ,r\sin \alpha ,o)$

$O$ is the origin

and the line $OP$ of length $r$ makes an angle $\alpha$ with $x$-axis lies in a coordinate plane containing $x$-axis,

then the coordinates of $P$ are $(r\cos \alpha ,o,r\sin \alpha )$

or $(r\cos \alpha ,r\sin \alpha ,o)$.