Question

1)calculate please it 2) prove it please

Answer 1

1. 2sin²(-2490) + tan(1410)
   2(0.25) - 0.6
   0.5 + 0.6
   1.1

2. $\frac{2sin(\alpha)cos(\beta) - sin(\alpha - \beta)}{cos(\alpha - \beta) - 2sin(\alpha)sin(b)} = tan(\alpha + \beta)$
    $\frac{2sin(\alpha)cos(\beta) - sin(\alpha)cos(\beta) + cos(\alpha)sin(\beta)}{cos(\alpha)cos(\beta) + sin(\alpha)sin(\beta) - sin(\alpha)sin(\beta)} = tan(\alpha + \beta)$
    $\frac{sin(\alpha)cos(\beta) + cos(\alpha)sin(\beta)}{cos(\alpha)cos(\beta) - sin(\alpha)sin(\beta)} = tan(\alpha + \beta)$
    $\frac{sin(\alpha + \beta)}{cos(\alpha + \beta)} = tan(\alpha + \beta)$
    $tan(\alpha + \beta) = tan(\alpha + \beta)$