37pts. what are the x-intercept and vertex of this quadratic function? g(x) = -5(x - 3)^2

This is geometry. could anyone ? i can't fail this class. my grade is quite low already.

Show algebraically that f and g are inverse functions f(x)=x^2/-6; g(x)=square root of 2x+12

The blue whale is the largest animal living on the earth. the average blue whale measures 100 feet long (30 meters) and weighs 300,000 pounds (136,000 kilograms). a whale’s head is 1⁄3 of the length of its body. a new baby whale is 1⁄4 the length of a grown whale. the average man is 1⁄17 the length of a blue whale, and 1⁄1,818 its weight. a human baby measures 1⁄4 of the length of an adult. calculate the following information: how long is a whale’s head? how long is a new baby whale? how tall is the average man? how much does the average man weigh? how tall is the average human baby?