can anyone tell me the value of x in the equation y=-cosx x=4pi?

Answer 1

-cosine(4 * pi) = -1


you can see the pattern below....

cosine (1 * pi) = -1
cosine (2 * pi) = 1
cosine (3 * pi) = -1
cosine (4 * pi) = 1 etc.....

but your equation was for -cosine not cosine

Answer 2

The value of x is 4 pi (given)

the value of y, IF the angle is given in radians, is -1

4 pi = 2 full turns = 720 degrees.
In trigonometry, that is equivalent to an angle of 0.
(if you start along a circle and move 720 degrees, you will have gone exactly twice around and will be back at your starting point of 0)

Cosine(0) = 1

Cosine = adjacent/hypothenuse. If the angle is 0, then the opposite side is 0 and the adjacent side must be 1 (same as the hypothenuse) because hypothenuse squared = opposite squared + adjacent squared.

- Cosine (0) = -1

Answer 3

Big_C is right, but the value of X is 4pi
In degrees that's 180x4 = 720

Answer 4

4 pi=4*180


1

Answer 5

y = -cos (4pi)
y = - cos(720)
y = -cos (720 - 360)
y = -cos (360)
y = -1