This is a right angle triangle
So we can use the tangent
tan x = 5/20
tan x= 0.25
x=tan^-1 (0.25)
x= 14.04 degrees
So yes you're correct
1.5 liters because it says she drinks 1.5 A DAY therefore she drink 1.5 liters of water each day
Simply plug in the value for x.
If x is equal to -18, then plug in -18 for x.
Example:
f(x) = 15 + x/5.
f(5) = 15 + 5/5.
Then solve the equation.
A function is just something that receives some value and then barfs a value out. This is an IO relationship. (Input/Output).
