Using the quotient rule find the first derivative of the function y=((3x+1)(cos2x))/e^2x

1 answer

To find the derivative of the function y = ((3x+1)(cos2x))/e^(2x) using the quotient rule, we need to find the derivatives of the numerator and denominator separately.

First, let's find the derivative of the numerator using the product rule:

dy/dx = (d/dx)[(3x+1)(cos2x)]
= (3)(cos2x) + (3x+1)(d/dx)(cos2x)

Using the chain rule, the derivative of cos2x is -2sin2x:

dy/dx = 3cos2x + (3x+1)(-2sin2x)

Next, let's find the derivative of the denominator:

dy/dx = (d/dx)[e^(2x)]
= e^(2x)(d/dx)(2x)

Using the chain rule, the derivative of 2x is 2:

dy/dx = e^(2x)(2)

Now, we can apply the quotient rule:

dy/dx = (denominator * derivative of numerator - numerator * derivative of denominator) / denominator^2

dy/dx = (e^(2x)(2)[(3cos2x) + (3x+1)(-2sin2x)] - [(3x+1)(cos2x)](2e^(2x))) / (e^(2x))^2

Simplifying the expression:

dy/dx = (2e^(2x)[3cos2x - (3x+1)(2sin2x)] - 2(3x+1)(cos2x)e^(2x)) / e^(4x)

dy/dx = (2e^(2x)(3cos2x - (3x+1)(2sin2x)) - 2(3x+1)(cos2x)e^(2x)) / e^(4x)

Therefore, the first derivative of the given function y = ((3x+1)(cos2x))/e^(2x) is (2e^(2x)(3cos2x - (3x+1)(2sin2x)) - 2(3x+1)(cos2x)e^(2x)) / e^(4x).