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Find the measures of two angles, one positive and one negative, that are coterminal with pi divided by four.

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User Jonathan H
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2 Answers

3 votes

Answer: The positive co-terminal angle is
(9\pi)/(4). and the negative co-terminal angle is
-(7\pi)/(4).

Step-by-step explanation: We are to find the measures of the two angles, one positive and one negative, that are co-terminal with pi divided by four.

We know that

any two co-terminal angles differ from each other by an integral multiple of
2\pi.

So, to find the positive co-terminal angle, we will add
2\pi to
\frac[\pi}{4} and to find the negative co-terminal angle, we will subtract
2\pi from
\frac[\pi}{4}.

Therefore, the required positive co-terminal angle is given by


C_p=(\pi)/(4)+2\pi=(\pi+8\pi)/(4)=(9\pi)/(4).

And, the required negative co-terminal angle is given by


C_n=(\pi)/(4)-2\pi=(\pi-8\pi)/(4)=-(7\pi)/(4).

Thus, the positive co-terminal angle is
(9\pi)/(4). and the negative co-terminal angle is
-(7\pi)/(4).

User Jan Kalfus
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7.4k points
4 votes

\frac{ \pi }is the 45 degree angle. the whole circle is 2π. so the positive angle is π/4+2π =(9 \pi )/(4)
the the negative angle is -(2π-π/4)= -\frac{7 \pi }{4}
User Simpatico
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7.8k points