By first differentiating (√(1-x))/(√(1+x)) obtain an expression dy/dx in terms of x. hence show that the gradient of the normal to the curve at point (x, y) is (1+x)(√(1-x^2))

then, the surface area of the sphere shown in the image is: 256π sq. units!

step-by-step explanation:

the lateral surface area of a sphere is 2πrh where h=2r.

then:

surface area = 4πr^2.

in this case, r=8 units ⇒ surface area = 4π(8 units)^2. = 256π sq. units!

then, the surface area of the sphere shown in the image is: 256π sq. units!