Identify an interval [-a,a] so that(adsbygoogle = window.adsbygoogle || []).push({});

|arctan(x)-x+x^3/3| < or = 10^-15

for all x E [-a,a]. Your result needs to be supported by a convincing proof

I'm not sure how to go about this... can someone help me out?

all i could probably do is... since.. 10^-15 is close to zero, i can find out what the x's are equal to... but, i don't know what else i can do.

How would i be able to find the x's if there's an arctan? Is there any trig identities that i use?

Thanks

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# Homework Help: Identifing an interval

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