Rheumatoid arthritis is a disorder in which the joints swell and cause pain. rheumatoid arthritis causes the body’s own immune cells to attack the membrane of the joints. which body system does rheumatoid arthritis affect?

nervous

musculoskeletal

integumentary

excretory

circulatory

It would be the musculoskeletal because the disorder focuses on the joints which are a part of the musculoskeletal body system.

answer: at 24 february, 2014 the population gets twice of its initial population.

explanation:

since we have given that

the population for alpha city, t years after january 1, 2004 is given as

first we find out the initial population, i.e. t=0,

so, our quadratic equation becomes,

according to question, we have said that if the population has twice its initial population, then it becomes

so, time taken to reach this above mentioned population is given by

now, we know that time can't be negative so, we take t=9.149 years.

hence, at 24 february, 2014 the population gets twice of its initial population.