Question

For the graph, what is a reasonable constraint so that the function is at least 300?

(Graph Below)

A) x ≥ 0

B) −5 ≤ x ≤ 30

C) 0 ≤ x ≤ 25

D) All real numbers

Answer 1

C) 0 ≤ x ≤ 25

Its correct! Hope this helps :)

Answer 2

C) 0 ≤ x ≤ 25

Explanation:

We are supposed to find a reasonable constraint so that the function is at least 300 i.e. the value of x at which f(x) is greater or equal to 300

A)x ≥ 0

Refer the graph

At x = 0

f(x)=300

On increasing the value of x , f(x) increases but at x = 12 it starts decreasing

So, x ≥ 0 can also have f(x)<300

So, Option A is wrong

B)−5 ≤ x ≤ 30

At x = -5

f(x) = 100

So, Option B is wrong since we require f(x) is greater or equal to 300

c)0 ≤ x ≤ 25

At x = 0

f(x)=300

At x = 12 , it starts decreasing

At x = 25

f(x)=300

So, The value of f(x) is at least 300 when 0 ≤ x ≤ 25

D)All real numbers

At x = 30

f(x)=0

But we require f(x) greater or equal to 300

Hence Option C is true