INCH
contestada

Suppose f(x) = aln(bx) where f(e) = 12 and f'(2) = 2. Find the constants a and b.

Respuesta :

Answer:

[tex]a=4[/tex]

[tex]b=e^2[/tex]

Step-by-step explanation:

We are given that

[tex]f(x)=aln(bx)[/tex]

f(e)=12

f'(2)=2

We have to find the constants a and b

Substitute x=e

[tex]f(e)=aln(be)[/tex]

[tex]12=aln(be)[/tex]

[tex]ln(be)=\frac{12}{a}[/tex]

[tex]f'(x)=\frac{a}{x}[/tex]

Using the formula

d(lnx)/dx=1/x

[tex]f'(2)=\frac{a}{2}[/tex]

[tex]2=\frac{a}{2}[/tex]

[tex]a=4[/tex]

Substitute a=4

[tex]ln(be)=12/4=3[/tex]

[tex]be=e^{3}[/tex]

[tex]b=e^{3}/e[/tex]

[tex]b=e^2[/tex]