Which interval or union of intervals represents the values for which ​f(x)​ is ≤ 0? Select the correct choice below and fill in the answer boxes to complete your choice.

(-∞, -1]∪{5}

Step-by-step explanation:

We know that:

f(x) ≤ 0 is true if the graph of the function is intersecting the x-axis or below the x-axis.

So we can just look at the graph, we can see that in the interval:

(-∞, -1]   (the value x = -1 is included, that is why we use the symbol ] instead of the parenthesis)

the graph is below or intersecting the x-axis

and this also happens at x = 5 or just denoted as {5}

Then the correct notation is:

(-∞, -1]∪{5}

the answer is the third / last answer

step-by-step explanation:

answer:   28.56 feet (approx)

step-by-step explanation:

since, triangle abc has measure of angle c equal to 55 degrees, measure of angle abc equal to 90 degrees, and length of bc equal to 20 feet.

we have to find out the measurement of segment ab.

therefore, tan 55° =

but bc = 20 feet.

⇒ tan 55 ° =  

⇒ ab = 20 × tan 55 °

⇒ ab = 20 × 1.42814800674

⇒ ab = 28.5629601348   ≈ 28.56 feet