Question

The point P=\left(-1/7, y) lies on the unit circle shown below. What is the value of y in its simplest form?

Answer 1

Step-by-step explanation:

The unit circle is a circle in the form of

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

while x = cos t

y= sin t

, where t is an angle

So we plug in -1/7, for x to find y

$( \frac{ - 1}{7} ) {}^{2} + {y}^{2} = 1$

${y}^{2} = \frac{49}{49} - \frac{1}{49}$

$y = \frac{4 \sqrt{3} }{7}$

If the point is in the 2nd quadrant, your value of y is positive

If it in the third quadrant, the y value is negative