Question

Solve the inequality: -x2 + 9 > 0.






A.

x < -3 or x > 3





B.

x < 3





C.

-3 < x < 3





D.

No solution

Answer 1

is it a or c?

Answer 2

i think c but not sure

Answer 3

-x2+9 = (-x+3)(x+3)

Answer 4

\[-x^2 + 9 > 0 \]easier to multiply by \(-1\) i.e. change the signs and start with
\[x^2-9<0\]

Answer 5

then factor as \((x-3)(x+3)<0\) and since this is a parabola that opens up, it is negative between the zeros and positive outside of them
we want where it is negative

Answer 6

as always, C is the answer
it is always C