Question

The arrangement of the following circles in the ascending order of their radii is
A) $r=8\cos \theta$
B) $r=6\sin \theta$
C) $r=8\cos \theta +6sin\theta$

• A. A, B, C
• B. C, A, B
• C. C, B, A
• D. B, A, C

Answer 1

Answer: (D)

B, A, C

A) $r=8cos\theta$
radius $=\sqrt{a^2+b^2}=\sqrt{8^2+0^2}=8$
B) $r=6sin\theta$
radius $=\sqrt{a^2+b^2}=\sqrt{0^2+6^2}=6$
C) $r=8cos\theta +6sin\theta$
radius $=\sqrt{a^2+b^2}=\sqrt{8^2+6^2}=10$
Therefore, $B<A<C$
Ans: D