Find a · b. |a| = 80, |b| = 50, the angle between a and b is 3π/4.

Over which interval is the graph of f(x) = x2 + 5x + 6 increasing?

If m∠abc = 70°, what is m∠abd? justify your reasoning.  using the addition property of equality, 40 + 70 = 110, so m∠abd = 110°.  using the subtraction property of equality, 70 − 30 = 40, so m∠abd = 30°.  using the angle addition postulate, 40 + m∠abd = 70. so, m∠abd = 30° using the subtraction property of equality.  using the angle addition postulate, 40 + 70 = m∠abd. so, m∠abd = 110° using the addition property of equality.

Is (0,0) a to ? ys x2 - 4 y> 2x-1