Answer:
Options (1) and (5)
Explanation:
Given function 'f' representing the relation between temperature of the oven after 't' minutes is,
f(t) = 0.25t² + 65
Option (1).
f(0) means that when the cake was placed in the oven, its temperature was 65°.
True.
f(0) = 0 + 65 = 65
Option (2).
To find the temperature after 15 minutes, we need to find 't' when f(t) = 15
False.
We have to find the value of f(15) to find the temperature of the oven after 15 minutes.
Option (3).
Temperature of the cake was 81° F when it was kept in the oven for 8 minutes.
Given statement is False.
It should be represented by,
f(8) = 81
Option (4).
After 10 minutes,the temperature of the cake was 71.25 degree F.
False.
By putting t = 10 in the function,
f(10) = 0.25(10)² + 65
= 25 + 65
= 90° F
Option (5).
The temperature of the cake when the baker takes it out of the oven, can be represented by,
f(30) = 290
True.
f(30) = 0.25(30)² + 65
= 225 + 65
= 290