PLEASE HELP An architectural engineer is designing a parabolic dome that will be 200 feet in diameter with a maximum height of 50 feet. Find the equation of the cross–sectional parabola of the dome.
A. (-x^2)/(400) - 5,000/400
B. (-x^2)/(200) - 10,000/200
C. (-x^2)/(400) - 5,000/50
D. (-x^2)/(400) - 5,000/2,000

What are the measures of ∠a, ∠b, ∠c and ∠d? explain how to find each of the angle measure.

For the equations below which statement is true ?

An initial investment of $100 is now valued at $150. the annual interest rate is 5%, compounded continuously. the equation 100e0.05t = 150 represents the situation, where t is the number of years the money has been invested. about how long has the money been invested? use your calculator and round to the nearest whole number. years