A lake near the artic circle is covered by sheet of ice during the cold winter months. When spring arrives, the ice starts to melt. S models the ice sheets thickness (in meters) after t weeks. S= -0.25t+4 What is the ice sheet's thickness at the beginning of spring?

4 meters

Step-by-step explanation:

Given

S models the ice sheets thickness (in meters) after t weeks. S= -0.25t+4

this model represent that

thickness of ice sheet will be  -0.25t+4 meters

thus

for example after 1 week

thickness of ice sheet will be found by putting t = 1

thickness of ice sheet after 1 week = -0.25*1+4 = -0.25 + 4 = 3.75 meters

we have to find thickness at the beginning of spring

at the beginning there will be zero weeks passes

thus,

we can find thickness at beginning of street by putting t = 0

thickness of ice sheets at the beginning of spring =  -0.25*0+4

thickness of ice sheets at the beginning of spring = 0+ 4 = 4 meters