Calculation: 6vNLyZ - 1
cos(a+b) =
cos(a)* cos(b)+ sin(a)* sin(b)
cos(a)* cos(b)+ sin(a)* sin(b)
|
cos(a+b) = cos(a)* cos(b)+ sin(a)* sin(b)$$cos(a+b)$$ = $$cos(a)\cdot cos(b)+sin(a)\cdot sin(b)$$
cos(a+b)- cos(a)* cos(b)- sin(a)* sin(b) = 0$$cos(a+b)-cos(a)\cdot cos(b)-sin(a)\cdot sin(b)$$ = $$0$$
2* sin(
)* sin(
) = 0$$2\cdot sin(\frac{a-b+a+b}{2})\cdot sin(\frac{a-b-a-b}{2})$$ = $$0$$
| (a-b+a+b) |
| / 2 |
| (a-b-a-b) |
| / 2 |
a = 0$$a$$ = $$0$$