High School

For the function [tex]s(x) = 20x^3 - 3x^5[/tex]:

A. (i) [tex]s'(x) = 60x^2 - 15x^4[/tex], (ii) [tex]s''(x) = 120x - 60x^3[/tex]
B. (i) [tex]s'(x) = 60x^2 - 15x^4[/tex], (ii) [tex]s''(x) = 120x^2 - 60x^4[/tex]
C. (i) [tex]s'(x) = 60x^2 + 15x^4[/tex], (ii) [tex]s''(x) = 120x - 60x^3[/tex]
D. (i) [tex]s'(x) = 60x^2 + 15x^4[/tex], (ii) [tex]s''(x) = 120x^2 + 60x^4[/tex]

Answer :

Final Answer

For the function s(x) = 20x³ - 3x⁵ :

(i) s'(x) = 60x² - 15x⁴, (ii) s''(x) = 120x - 60x³

Thus the correct option is A

Explanation

We need to find the first and second derivatives of the function

s(x) = 20x³ - 3x⁵. Here's how to solve it:

First derivative (s'(x)):

Apply the power rule:

d/dx(x^n) = nx^(n-1).

s'(x) = d/dx(20x³) - d/dx(3x⁵)

= (3 * 20x²) - (5 * 3x⁴) = 60x² - 15x⁴

Second derivative (s''(x)):

Differentiate s'(x) which is a polynomial.

s''(x) = d/dx(60x²) - d/dx(15x⁴)

= (2 * 60x) - (4 * 15x³) = 120x - 60x³

Therefore, the first derivative is

s'(x) = 60x² - 15x⁴ and the second derivative is

s''(x) = 120x - 60x³.