suppose u and v are functions of x that are differentiable at x=0 and that u(0)=5, u'(0)=-5, v(0)=8, and v'(0)=-2.find the values of the following derivatives at x=0

a)d/dx(uv)=?

b)d/dx(u/v)=?

c)d/dx(v/u)=?

d)d/dx(-6v-9u)=?

Respuesta :

Answer:

a)-50

b)-15/32

c) 6/5

d) 57

Explanation:

a)

[tex]\frac{d}{dx}(uv)[/tex]

[tex]u(x)v'(x)+u'(x)v(x)[/tex]

Evaluate this at [tex]x=0[/tex] we get:

[tex]u(0)v'(0)+u'(0)v(0)[/tex]

[tex]5(-2)+-5(8)[/tex]

[tex]-10+-40[/tex]

[tex]-50[/tex]

b)

[tex]\frac{d}{dx}(\frac{u}{v})[/tex]

[tex]\frac{u'(x)v(x)-u(x)v'(x)}{(v(x))^2}[/tex]

Evaluate this at [tex]x=0[/tex] we get:

[tex]\frac{u'(0)v(0)-u(0)v'(0)}{(v(0))^2}[/tex]

[tex]\frac{-5(8)-5(-2)}{(8)^2}[/tex]

[tex]\frac[-40+10}{64}[/tex]

[tex]\frac{-30}{64}[/tex]

[tex]\frac{-15}{32}[/tex]

c)

[tex]\frac{d}{dx}(\frac{v}{u})[/tex]

[tex]\frac{v'(x)u(x)-v(x)u'(x)}{(u(x))^2}[/tex]

Evaluate this at [tex]x=0[/tex] we get:

[tex]\frac{v'(0)u(0)-v(0)u'(0)}{(u(0))^2}[/tex]

[tex]\frac{-2(5)-8(-5)}{(5)^2}[/tex]

[tex]\frac{-10+40}{25}[/tex]

[tex]\frac{30}{25}[/tex]

[tex]\frac{6}{5}[/tex]

d)

[tex]\frac{d}{dx}(-6v-9u)[/tex]

[tex]-6v'(x)-9u'(x)[/tex]

Evaluate this at [tex]x=0[/tex]:

[tex]-6v'(0)-9u'(0)[/tex]

[tex]-6(-2)-9(-5)[/tex]

[tex]12+45[/tex]

[tex]57[/tex]