Find sin x/2, cos x/2, and tan x/2 from the given information.. cos x = −15/17, 180° < x < 270°. sin x/2=. cos x/2=. tan x/2=

Trigonometry is the science of mathematics that studies the relationship between sides and angles in triangles

In a cartesian plane, the angle α can vary from 0 ° to 360 °, counterclockwise

This coordinate field is divided into 4 quadrants:

For half angle we can find it from double angle

Trigonometry Formulas for Double Angles:

sin 2A = 2 sin A cos A

cos 2A = 1 - 2 sin²A = 2cos²A-1

tan 2A = 2 tan A / 1-tan²A

then:

cos 2A = 2cos²A-1

cos 2A = 1-2 sin²A

in the same way

input the value : cos x = −15/17

Because x in the quadrant III (180° < x < 270°) , then

For quadrant I, only sin have positif value, for cos and tan have negatif value

trigonometric ratio

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Prove the converse of the Pythagorean Theorem

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Use Pythagoras' theorem

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the triangle angle  

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for finding the midpoint of any given 2 pair of points simply add the respective x coordinates with other x coordinate and the y coordinate with other y coordinate and divide them by 2

in your question it will be :

(3+1)/2 for the x coordinate of mid point i.e 2

[8+(-4)]/2 for the y coordinate of midpoint i.e 2

so coordinates of mid point of points (3,8) and (1,-4) will be (2,2)