How do you differentiate y=37-sec^3(2x)y=37sec3(2x)?

1 Answer
Nov 2, 2016

y'=-6sec^3(2x) tan(2x)

Explanation:

Differentiating y is determined by applying the power and chain rule

Let u(x)=sec^3x and v(x)=2x
Then f(x) is a composite function of u(x) and v(x)
Thus f(x)=u@v(x)

color(red)(f'(x)'=u'(v(x))xxv'(x)

u'(x)=??
Applying the power rule differentiation
color(blue)((x^n)'=nx'x^(n-1))

u'(x)=(sec^3x)'=3xxsec^(3-1)xx(secx)'
u'(x)=3sec^2x xxsecxtanx
u'(x)=3sec^3x tanx

u'(v(x))=3sec^3(v(x)) tan(v(x))

color(red)(u'(v(x))=3sec^3(2x) tan(2x))

color(red)(v'(x)=2)

color(red)(f'(x)=u'(v(x))xxv'(x)

f'(x)=3sec^3(2x) tan(2x)xx2
f'(x)=6sec^3(2x) tan(2x)

y'=(37)'-f'(x)
y'=0-f'(x)
y'=-6sec^3(2x) tan(2x)