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QUICK! 75 POINTS !!Select all that are part of the solution set of csc(x) > 1 and over 0 ≤ x ≤ 2π.

QUICK! 75 POINTS !!Select all that are part of the solution set of csc(x) > 1 and-example-1
User Smarie
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2 Answers

2 votes

Answer:

x= pi/4

x= 5pi/6

Explanation:

QUICK! 75 POINTS !!Select all that are part of the solution set of csc(x) > 1 and-example-1
User Fernand
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5.2k points
1 vote

Answer:


(\pi)/(4)


(5\pi)/(6)

Explanation:

The answer uses the unit circle and that sine and cosecant are reciprocals.

The first choice doesn't even fit the criteria that
x is between
0 and
2\pi (inclusive of both endpoints) because of the
x=(-7\pi)/(6).

Let's check the second choice.


\csc((\pi)/(4))=(2)/(√(2)) \text{ since } \sin((\pi)/(4))=(√(2))/(2).


\csc((\pi)/(4))>1 \text{ since } (2)/(√(2))>1


\csc((\pi)/(2))=1 \text{ since } \sin((\pi)/(2))=1 which means
\csc((\pi)/(2))=1 which is not greater than 1.

So we can eliminate second choice.

Let's look at the third.


\csc((5\pi)/(6))=2 \text{ since } \sin((5\pi)/(6))=(1)/(2) which means
\csc((5\pi)/(6))>1.


\csc(\pi) isn't defined because
\sin(\pi)=0.

So we are eliminating 3rd choice now.

Let's look at the fourth choice.


\csc((7\pi)/(6))=-2 \text{ since } \sin((7\pi)/(6))=(-1)/(2) which means
\csc((7\pi)/(6))<1 and not greater than 1.

I was looking at the rows as if they were choices.

Let me break up my choices.

So we said
x=-(7\pi)/(6) doesn't work because it is not included in the inequality
0\le x \le 2\pi.

How about
x=0? This leads to
\csc(0) which doesn't exist because
\sin(0)=0.

So neither of the first two choices on the first row.

Let's look at the second row again.

We said
(\pi)/(4) worked but not
(\pi)/(2)

Let's look at the choices on the third row.

We said
(5\pi)/(6) worked but not
x=\pi

Let's look at at the last choice.

We said it gave something less than 1 so this choice doesn't work.

User Eigenharsha
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5.8k points