Refreshers and/or solutions

lilrockfreekshow

New member
Joined
Jan 7, 2006
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3
Ok here's the first problem

Let f be the function defined by f(x)=(1+tan x)^(3/2)

a) Write an equation for the line tangent to the graph of f at the point where x=0
b)Using the equation found in part (a), approximate f(0.02)
c)Let f^-1 denote the inverse function of f. Write and expression that gives f^-1(x) for all x in the domain of f^-1

Someone tell me what to use exactly to do these. I don't need the actual solution, just how to do it.
 
Here are some hints,
\(\displaystyle \L
f'(x) = \frac{3}{2}\left( {1 + \tan (x)} \right)^{\frac{1}{2}} \left( {\sec ^2 (x)} \right)\)


\(\displaystyle \L
\begin{array}{c}
x = \left( {1 + \tan (y)} \right)^{\frac{3}{2}} \\
x^{\frac{2}{3}} = 1 + \tan (y) \\
y = \arctan \left( {x^{\frac{2}{3}} - 1} \right) \\
\end{array}\)
 
Ok well since I can't figure this one out and I have a whole packet of ten problems, all different. I give up, I'll let my teacher explain them. I'll go after school for help or something.

Thanks for your hints though.
 
Don't give up that easy!. pka gave you the derivative(f'(x)) of the function. That's

the slope. You know, the m in y=mx+b.

They want the slope at x=0. Enter x=0 into the derivative and see what you get.

Enter x=0 into the original function to get y, then set up your line equation and

solve for b. You know x=0 already.
 
Now I remember... wow... 2 weeks of vacation and my brain goes... pll...

Thank you so much, now that makes things clearer on the other problems too!
 
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