Answer:
Step-by-step explanation:
I think your question missed key information, allow me to add in and hope it will fit the orginal one
<em>For the graph below, what should the domain be so that the function is at least 200? graph of y equals minus 2 times the square of x plus 30 times x plus 200 </em>
My answer:
Given the above information, we have:
To make the function is at least 200, it means that:
≥ 200
<=> ≥ 0
<=> x(-2x+30) ≥ 0
This is the product of two numbers hence would be positive only if either both are positive or both are negative
- Case I: Both positive
x ≥ 0 and (-2x+30) ≥ 0
<=> 0 ≤ x ≤ 15
- Case II: Both negative
Then we get
This is inconsistent as a value cannot be less than 0 and greater than 15
=> our correct answer is
Hope it will find you well.