Given:
To find:
The exact value of cos(u-v) if both angles are in quadrant 3.
Solution:
In 3rd quadrant, cos and sin both trigonometric ratios are negative.
We have,
Now,
On further simplification, we get
Similarly,
Now,
Therefore, the value of cos (u-v) is 0.1872.
So firstly, I'm going to be converting the mixed number into an improper fraction. To do this, multiply the whole number by the denominator and then add that product with the numerator and that will be your new numerator. In this case:
3 × 8 = 24, 24 + 3 = 27.
Now since they have the same denominator, you can subtract the numerators.
Now simplify the number as such:
<u>In short, your answer is -17/4, or -4 1/4.</u>