No clue about these! asap and i will reward points!

What is f(3) for the quadratic function f(x)= 2x^2+ + x - 12

The dolphins at the webster are fed 1/2 of a bucket of fish each day the sea otters are fed 1/2 as much fish as the dolphins how many buckets of fish are the sea fed each day? simplify you answer and write it as a proper fraction or as a whole or mixed number

An arc subtends a central angle measuring 7pi/4 radians what fraction of the circumference is this arc?