Question

(b) When
When a, & be given, obtain a formula
to find , b, where the symbols have
their usual meanings.
(0) If be the angle subtended at the earth
by the sun and a stationary point of
a planet's orbit and be the maximum
elongation of the planet, prove that
Ф
2 cot0 = sec +cosec
2
2
(d) Explain the term 'direct and retrograde
motion'.​

Answer 1

Step-by-step explanation:

direct motion of a planetary body in a direction similar to that of other bodies within its system, and is sometimes called prograde motion. Retrograde motion is motion in the opposite direction. In the case of celestial bodies such as the retrograde Carme group of moons, such motion may be real, defined by the natural rotation or orbit of the body.