PreCal
posted by Hannah on .
1)find f(g(x))
f(x) = x^2 + 2x g(x) = 1/x
x^3 + 2x
Is this correct?
2) solve: 3^x1 = 10
ln 3/ ln 10 = .264
Is this correct? I am not sure how to do these.
3) Solve: 3^x+2  4 = 12

no to both answers
1. f(x) = x^2 + 2x , g(x) = 1/x
then
f(g(x)
= f(1/x)
= (1/x)^2 + 2(1/x) = 1/x^2 + 2/x or (1+2x)/x^2
2.
the way you typed it, ...
3^x  1 = 10
3^x = 11
x = ln11/ln3 = 2.182658
If you meant to type
3^(x1) = 10
then
x1 = ln10/ln3
x = ln10/ln3 + 1
=3.0959
3. Again I don't think you meant what you typed
Was it 3^(x+2)  4 = 12 ???
if so then ...
3^(x+2) = 16
x + 2 = ln16/ln3
x = ln16/ln3  2 = .5237