Question

Q3: Find the values of e, a, b, and c for r = 21/5-2 cos theta.

Answer 1

The answer choice is C

Explanation:

No

Answer 2

e = 2/5

a = 5

b = √21

c = 2

Explanation:

The first step is to write the given polar equation in standard form by dividing the numerator and denominator by 5;

`r=((21)/(5) )/(1-(2)/(5)costheta )`

The eccentricity of this conic section is thus 2/5, the coefficient of cos theta. Nevertheless, the eccentricity of a conic section can also be evaluated using the equation;

`e=(c)/(a)`

This implies that ;

a = 5

c = 2

The value of b is determined using the relation;

`b^(2)=a^(2)-c^(2)   \\b=√(25-4) \\b=√(21)`