Question

Point A lies on the circumference of the unit circle and is in the first quadrant. If the x-coordinate of the point is 0.12, its y-coordinate is .

Answer 1

Answer

0.99

Explanation

Point A forms a right triangle.

Hypotenuse, c = 1 unit

Base length, x = 0.12 units

Then using the Pythagoras theorem,

y² = c² - x²

y² = 1² - 0.12²

    = 2 - 0.0144

   = 0.9856

y = √0.9856

   = 0.992773891

Answer to the nearest hundredths is 0.99.

Answer 2

we are given

Point A lies on the circumference of the unit circle

so, we can write equation of circle as

$x^2 +y^2 =1^2$

now, we are given

$x =0.12$

so, we can plug it in equation and find y

$0.12^2 +y^2 =1^2$

$y^2=0.9856$

$y=\sqrt{0.9856},\:y=-\sqrt{0.9856}$

Since, point-A lies in first quadrant

so, both x-value and y-value will be positive

so, we get

$y=\sqrt{0.9856}$.............Answer