Question

Pls help! evaluate the sine of the real number, pls give exact answers

Answer 1

Answer:

 $-\frac{\sqrt2}{2}$  or exact is −0.70710678...

Step-by-step explanation:

Getting the point!

1. If we look at the unit circle and we find $-\frac{3\pi }{4}$ we see it is in the 3rd quadrant.
2. We know that all points in the 3rd quadrant have both negative x and negative y values.
3. We know that all radians with the base of 4 on the unit circle have the points of $(\frac{\sqrt{2}}{2} ,\frac{\sqrt{2}}{2})$
4. Because we are in the 3rd quadrant and both x and y are negative we know the point of $-\frac{3\pi }{4}$  is $(-\frac{\sqrt{2}}{2}, -\frac{\sqrt{2}}{2})$

Finding the sin!

1. Because we know that sin is asking us for the y value
2. We can just look at the point and find the y value!
3. the y value is $-\frac{\sqrt2}{2}$
4. Because this fraction does not need to be rationalized we are good!
5. Use a calculator to find the exact value and you get -0.70710678...
6. The final answer is  $-\frac{\sqrt2}{2}$ or exact is −0.70710678...

Hope this helps!! Please mark Brainliest!