Originally Posted by

**pantera** Hello, I need help finishing this problem. Use one-sided limits to find values of the constants a and b that make the piecewise function differentiable at the point where the function rule changes.

f(x) = e^(ax), if x <1

and

f(x) = b + ln x, if x>1

Here's what I have so far.....

For f to be continuous at x = 1,

lim as x goes to 1 from the left of e^(ax)= lim as x goes to 1 from the right of (b+ ln x)

implies e^(a)=b

For f to be differentiable at x = 1,

lim as x goes to 1 from the left of ae^(ax)=lim as x goes to 1 from the right of (1/x)

implies ae^(a) = 1

So I'm having trouble solving for a and b for these two equations....

e^(a)=b

ae^(a) = 1

The solution says solve by grapher: a = 0.5671....and b = 1.7632....,

but I don't know how to get that.

Thanks