Question

Find dy/dx when x = 1 , given that
y = (x^2 + 3) ( 2 - 4x - 5x^2)

Answer 1

product rule = f(x)g'(x) + g(x)f'(x)
(x^2+3)(-10x -4) + (-5x^2 -4x +2)(2x)
= (-10x^3 - 4x^2 - 30x -12) + (-10x^3 - 8x^2 +4x)
= -20x^3 -12x^2 -26x -12
Take out a (-2)
-2(10x^3 + 6x^2 + 13x + 6)
add in x = 1
-2( 10 + 6 + 13 + 6) =
-2(35)
(dy/dx) = -70 when x = 1

Answer 2

wow thank you so much

Answer 3

no problem