An object 20cm high is placed 40cm from a lens of focal length 24cm. Calculate:

Question

a) The power of the Lens?

b) The distance from the lens to the position of the image?

Answer 1

b) 1/p + 1/q = 1/f so
1/40 + 1/q = 1/24
a)I assume they mean magnification M = -q/p

Answer 2

The gradient of a curve is defined by

dy/dx = 3x^(1/2) - 6

Given the point (9, 2) lies on the curve, find the equation of the curve