Question

Piecewise functions, please help!
I don’t understand these- and my teacher isn’t answering emails. Any thoughts?

Answer 1

Answer:

Correct answer is 93

Step-by-step explanation:

1. Student gave incorrect answer

2. The function has 3 different conditions:

Depending on values of x (on the right side), you use one of the functions:

• if x<3 use function f(x)= -x-4
• if x is between 3 and 10 both inclusive (3≤x≤10) then use function f(x)=x²-7
• if x>10 then use function f(x)=120/x + 5

3. Correct function for x=10 is the middle function:

• f(x)=x²-7
• f(10)=100-7=93

The student A used:

• f(x)=120/x + 5

• f(10)=120/10 + 5=12+5=17

which is incorrect as this is good for values of x greater than 10.

Hope is helps to understand this better.