A = P + SI
A-P = SI
5425-5000 = 425
THEREFORE THE SIMPLE INTRESTE IS $425
SI = PTR/100
425 = 5000×1×R/100
425×100/5000×1=R
425×100÷5,000×1 = 8.5%
THEREFORE THE RATE IS 8.5%
The answer is the first one, (2)
Your function f(x)=(x^(1/3))(x+4)
What your going to want to do first is calculate your first derivative.
You will want to use both the power rule and the product rule.
f '(x)=(x+4)/x^(2/3)+x^(1/3)
f '(x)=4/3(x^(-2/3))(x+1)
Now find the critical numbers
4/3(x^(-2/3))=0 x+1=0
x=0, x=-1
Now plug numbers on the intervals (-infinity, -1),(-1,0) and (0,infinity) into the derivative of your function. The numbers I would choose are -2, -1/2 and 1.
Since f '(-2) is negative, f '(-1/2) is positive and f '(1) is positive, (-1,-3) and (1,5) are relative extrema. This means that the function f(x)=(x^(1/3))(x+4) is increasing on the interval (-1,0) U (0,infinity).
