Calculate Perihelion Distance of Mars Using Solar System Parameters

[ZedCar]

Homework Statement

Assuming that the sun lies at the principal focus of the solar system, and given that the semi-major axis and eccentricity of Mars is 1.5237 AU and 0.0934 respectively, calculate:

The distance (in AU) when Mars is closest to the Sun (known as perihelion). The angle θ=0°

Homework Equations

r = a(1 - e^2) / (1 +e cos θ)

The Attempt at a Solution

The correct solution is 1.38 AU

Though if I use the above eqn putting a=1.5237 and e=0.0934 I get an answer of 16.17.

Thanks for any help!

 

[gneill]

Must be finger problems with the calculator

What values do you calculate for the numerator and denominator of the expression?

 

[ZedCar]

Sorry about that! I'm getting the correct answer now...!