How does​ Cavalieri's Principle apply to finding the volume of a​ hemisphere? Explain.

Can someone answer these problems for me

Simplify 6sin θsec θ. choices a) 6 tan θ b) 6 cos θ c) 6 cot θ d) 6

To solve the system of equations below, grace isolated the variable y in the first equation and then substituted into the second equation. what was the resulting equation? 3y=12x x^2/4+y^2/9=1