#3 sin(x) = -sqrt(2)/2 so x = 315 degrees. So we have sin(x+pi/3) = sin(375) = sin(15) which in exact form would be (sqrt(3) -1)/(2sqrt(2))
#4 to find x we take the arctan(20/21) which is approximately 43.6 degrees and add 180 to it since it's in the 3rd quadrant which is 223.6 degrees so we do sin(223.6 + 90) = sin(313.6) which equals -21/29. This can also be done with the pythagorean theorem. -21/29.
#5 13^2 - 5^2 = 12^2. so sin is -12/-13 = 12/13. we take arcsin of that and add 180 and then divide by 2 and take the sin of that and its approximately 3/sqrt(13).
#6 sin is 4/5 so we take arcsin of that and get 143.13 which -60 is 83.13 and we take the sin of that to get 3/10 + 2sqrt(3)/5
Hope this helped :L
All but C can be used to gather resources.
A product of two (or more) factor can be zero if and only if at least one of the factors is zero.
In other words, you cannot multiply two non-zero real numbers, and have zero as a result.
So, if we want the product of these two factors to be zero, at least one of them has to be zero.
The first factor is zero if
The second factor is zero if
