Hi again! I posted a pic 27.bmp of my work...Can someone please check me? It's a radius of convergence problem...The pic is posted. Thanks! :o)

Question

Hi again!  I posted a pic 27.bmp of my work...Can someone please check me? It's a radius of convergence problem...The pic is posted. Thanks! :o)

anonymous · Answer

attachment

anonymous · Answer

Sorry if I was sloppy...I was writing really fast...lol :o)

amistre64 · Answer

the radius does not include an "x"

anonymous · Answer

uh oh...

anonymous · Answer

do you know where I went wrong?

amistre64 · Answer

your limit is stuff is fine till the end when you do that <1

amistre64 · Answer

$$|\frac{f(x)}{5}|<1$$
$$|f(x)|<5$$

anonymous · Answer

ok...so i should have multiplied both sides by 5...then what?

amistre64 · Answer

f(x) = (2x+3)(5x-71); so it has intercepts at x=-3/2 and x=71/5

since it expands to a positive leading coeff; its a parabola that opens up

anonymous · Answer

or should i have foiled (2x+3)(5x-71) earlier and then multiplied by 5?

amistre64 · Answer

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