Question

Find the range of

$f(x) = \frac{1}{4 - {x}^{2} }$
​

Answer 1

Answer:

f(x)<0 and f(x)≥1/4

Step-by-step explanation:

1/(4-x²) = y

1=4y-x²y

-yx²+4y-1=0

ax²+bx+c=0

a=-y; b=0; c=4y-1

descriminant = b²-4ac = 0-4(-y)(4y-1)

=4y(4y-1)≥0

y≤0 and y≥1/4

if we put 0 in y then f(x)=1/(4-x²) =0 no solution hence 0 is excluded then

f(x)<0 and f(x)≥1/4