gaokao 2018 Q15

gaokao · China · national-II-science 5 marks Addition & Double Angle Formulae Trigonometric Equation Solving via Identities

Given $\sin \alpha + \cos \beta = 1 , \cos \alpha + \sin \beta = 0$, then $\sin ( \alpha + \beta ) = \_\_\_\_$.

Given $\sin \alpha + \cos \beta = 1 , \cos \alpha + \sin \beta = 0$, then $\sin ( \alpha + \beta ) = \_\_\_\_$.