Recall that
sin(<em>a</em> + <em>b</em>) = sin(<em>a</em>) cos(<em>b</em>) + cos(<em>a</em>) sin(<em>b</em>)
sin(<em>a</em> - <em>b</em>) = sin(<em>a</em>) cos(<em>b</em>) - cos(<em>a</em>) sin(<em>b</em>)
Adding these together gives
sin(<em>a</em> + <em>b</em>) + sin(<em>a</em> - <em>b</em>) = 2 sin(<em>a</em>) cos(<em>b</em>)
To get 14 cos(39<em>x</em>) sin(19<em>x</em>) on the right side, multiply both sides by 7 and replace <em>a</em> = 19<em>x</em> and <em>b</em> = 39<em>x</em> :
7 (sin(19<em>x</em> + 39<em>x</em>) + sin(19<em>x</em> - 39<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
7 (sin(58<em>x</em>) + sin(-20<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
7 (sin(58<em>x</em>) - sin(20<em>x</em>)) = 14 cos(39<em>x</em>) sin(19<em>x</em>)
Answer:
B
Step-by-step explanation:
Not much to explain
Answer:just drag across
Step-by-step explanation:
To evaluate two fractions being divided, you must turn the right fraction into a reciprocal. That means you must put the bottom number at the top and then put the top number on the bottom (you’re basically switching them).
8/13 / 3/2
Now, once you turned the other number into a reciprocal, you multiply across. The top number times the other top number and do this to the bottom numbers, too.
8/13 * 3/2 = 24/26
You found the answer, 24/26. But as you can see, it’s not one of the choices. That’s because you need to simplify.
24/26 / 2/2 = 12/13
12/13 is your answer, or choice C!
I hope this helped. Comment below if you have any questions.
