Question

Distance of the point (a cos teta, a sin teta) from origin is :
(a) a
(b) a²
(c) ±a
(d) 1​

Answer 1

Answer:

distance from origin=√x²+y²

=√(a cos theta)²+(a sin theta)²

=√a²cos²theta+a²sin²theta

=√a²(cos²theta+sin²theta)

[sin²theta+cos²theta=2]

=√a²×1

=√a²

=a

Hence option (a) is correct.