The function is f(x)=x^2+4x-1
Ty

the function is decreasing on the interval (-∞,-2) and increasing on the interval (-2,∞)

B

Step-by-step explanation:

first we take the first derivative

x²+4x-1 = 2x+4

set this equal to 0 and solve

2x+4= 0

2x= -4

x= -2

we then have two intervals

(-∞,-2) u (-2,∞)

to find out whether something is decreasing on increasing on these intervals just plug in any number in the interval

if the result is positive it's increasing

if it's negative it's decreasing

Let's plug in x= -4 for the interval (-∞, -2)

2(-4)+4= -4

it's negative so it's decreasing on this interval

let's then plug in x=0 for the interval (-2,∞)

2(0)+4= 4

this is positive so it's increasing on this interval

So the function is decreasing on the interval (-∞,-2) and increasing on the interval (-2,∞)

which is equal to to B

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hope this !