Question

Can someone help asap?

Answer 1

Answers:

• sin = -5/13
• tan = 5/12
• csc = -13/5
• sec = -13/12
• cot = 12/5

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Explanation:

The angle theta is between pi and 3pi/2, excluding both endpoints.

This places theta in the third quadrant (Q3) between 180 degrees and 270 degrees. The third quadrant is in the southwest.

Plot point A at the origin. 12 units to the left of this point, will be point B. So B is at (-12,0). Then five units lower is point C at (-12,-5). Refer to the diagram below. Notice how triangle ABC is a right triangle.

The angle theta will be the angle BAC, or simply angle A.

Since cos(theta) = -12/13, this indicates that

AB = -12 = adjacent

AC = 13 = hypotenuse

Technically, AB is should be positive, but I'm making it negative so that we can then say

cos(angle) = adjacent/hypotenuse

cos(theta) = AB/AC

cos(theta) = -12/13

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If you apply the pythagorean theorem, you should find that BC = 5, which I'll  make negative since we're below the x axis. Then we can say

sin(theta) = opposite/hypotenuse

sin(theta) = BC/AC

sin(theta) = -5/13

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If you divide sine over cosine, then you'll get 5/12. The 13's cancel out. This is the value of tangent.

Or you could say

tan(theta) = opposite/adjacent

tan(theta) = BC/AB

tan(theta) = (-5)/(-12)

tan(theta) = 5/12

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To find csc, aka cosecant, you apply the reciprocal to sine

sin = -5/13 which means csc = -13/5

sec, or secant, is the reciprocal of cosine

cos = -12/13 leads to sec = -13/12

and finally cotangent (cot) is the reciprocal of tangent

tan = 5/12 leads to cot = 12/5

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Note: everything but tan and cot is negative in Q3.