We have seen the number 1,618 (1,61803398 to be more accurate), in three different situations ● the ratio of the terms of the Fibonacci sequence
● continued square roots
● continued fractions.

This number is called ‘phi’ or . It is an important number and is also called the Golden ratio. has many special properties. Let

1. Write down the value of (1)
2. What do you notice? (2)
3. Use the fact that to solve for and show that .

Which pair of lines is parallel? a. y=4x+1 and y+4=5 b. y=-2+x and 2y-2x=-2 c. y=1/4x + 2 and y-2=1/2x d. y=1/5x+1 and 5y+x= 10

F(x)= 1/x-4, g(x)=4x+1/x a. use composition to prove whether or not the functions are inverses of each other. b. express the domain of the compositions using interval notation.

Nthe opening scene of the movie raiders of the lost ark, indiana jones replaces a golden statue with a bag of sand. the platform on which the statue is placed is designed to detect the mass of the statue. if the bag of sand has a different mass than the statue, then a mechanism triggers and destruction ensues. the density of gold is about 20\text{ g/cm}^320 g/cm 3 20, space, g, slash, c, m, start superscript, 3, end superscript. the density of sand can be estimated at 2.5\text{ g/cm}^32.5 g/cm 3 2, point, 5, space, g, slash, c, m, start superscript, 3, end superscript. the gold statue can be modeled as a cylinder with height 25\text{ cm}25 cm25, space, c, m and radius 8\text{ cm}8 cm8, space, c, m. in terms of \piπpi, what is the mass of sand indiana jones needs to avoid triggering the mechanism?