graphs of exponentials and logarithms- help! (1 Viewer)

[poopoohead]

Hey,

i need some help with drawing graphs of e's and logs

ok-

With graphs of exponential- just the e to the power x graph- where abouts on the y axis does it cross- is it at 1- like other exponentials??? Or does it cross at e?

im stupid

What happens to the log graph when you add or subtract a number inside the brackets ie ln(x+1)???

What happens when you add or subtract a number to the whole thing- like
1 + ln(x) or 1+ ln(x +1)???

anyone help?

 

[Riviet]

e^x has y-intercept at y=1.

For y=ln(x-a), the graph y=lnx is shifted to the right by a units.

For y=ln(x+a), the graph y=lnx is shifted to the left by a units.

For y=lnx + k, the graph y=lnx is shifted up by k units.

For y=lnx - k, the graph y=lnx is shifted down by k units.

Combining two of the rules, for y=ln(x-a) + k, the graph y=lnx is shifted to the right by a units AND shifted up by k units.