Income - elasticity of demand HELP PLEASE!!!!!!!?

Question

I don't understand how to do these q's and how to get to the answer, please help.

1. y = e^-x^4

2. y = 2x + 2/x

3. y = -1/b loge (a/x) [ the e after log is smaller and meant to be slightly lower and the -1 is above the b]

Thanks in advance.

Cheers

Answer 1

E=(δQ/δP) * P/Q

Does your formulas represent demand equations or inverse demand?

Y=Q

X=P

In general solution is simple - you should apply relevant calculus rules here:

1:

δy/δx = δ(e^ (-x^4))/δx = -4e^(-x^4) * x³

E= -4e^(-x^4) * x³ * x / (e^ (-x^4)) = -4*x^4

2:

δy/δx = 2-2/x²

E=(2-2/x²) * x / (2x + 2/x) = (x² - 1) / (x² + 1)

3:

δy/δx = 1/(bx)

E = (x/(bx)) / (-1/b Ln(a/x) ) = - 1 / Ln(a/x)