Question

Which is the largest interval over which the function in the table is increasing?

Answer 1

Solution given:

y=-1/2 x²

for

f(x)=-1/2 x².

differentiating each term with respect to x

f'(x)=-x

when

x=-4

f'(-4)=4>0 increasing

when

x=-2

f'(-2)=2 >0 increasing

when x=0

f'(0)=0 stationary point.

other points are decreasing

so

largest interval of increasing is

A.X<-2