Question

Please help

4. The equation of a curve is y = (3 - 2x)^3 + 24x.
(a) Find an expression for dy/dx

5. The equation of a curve is y = 54x - (2x - 7)^3.
(a) Find dy/dx​

Answer 1

(4) y = (3 - 2x)³ + 24x

Use the power and chain rules:

dy/dx = 3 (3 - 2x)² d/dx [3 - 2x] + 24

dy/dx = 3 (3 - 2x)² (-2) + 24

dy/dx = -24x ² + 72x - 30

(5) y = 54x - (2x - 7)³

Same basic procedure:

dy/dx = 54 - 3 (2x - 7)² d/dx [2x - 7]

dy/dx = 54 - 3 (2x - 7)² (2)

dy/dx = -24x ² + 168x - 240