Question

What is the range of y = -x^2 - 8x - 10.

The solutions are:

All real numbers
y ≥ -2
y ≤ 6
y ≤ -4

I think it's y ≤ 6

Am I correct?

Answer 1

Yeah you're right:)

Answer 2

Just use differentiation to find the extrema of this function, in this case it's a maxima. Find the max value and the function's range would be -infinity to the max value or
\[ y\le max value\]