Posted by **terra** on Monday, October 24, 2011 at 7:34pm.

Show that tan^3(x)-8(tan^2(x))+17(tan(x)0-8 = 0

has a root in [0.5, 0.6]. Apply the Bisection Method twice to find an interval of length 0.025 containing this root.

I have NO idea where to go with that equals 0 part...I could figure it without it but that throws me off completely..you can't plug any numbers in

- calculus -
**Steve**, Monday, October 24, 2011 at 11:57pm
If there is a root in [0.5,0.6] then that means that f(.5) * f(.6) < 0

That is, the graph crosses the axis there somewhere, and the function changes sign.

f(.5) = -0.9374

f(.6) = 0.2062

So, bisect the interval

f(.55) = -0.3539

Still negative, so bisect again

f(.575) = -0.0708

Still negative, so the root is in [0.575,0.6]

In fact, it turns out to be 0.5813

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