Find a b ab 4a 5b 4a 5b and a a l angle 2 2 r angle b 3

Find a +b, a-b, 4a + 5b, 4a - 5b, and ||a|| a = -l angle 2, -2 r angle, b = 3 langle0, -2 r angle a + b = (-2, 4) a-b = _____ 4a + 5b = ____ 4a -5b=_____ ||a|| = _______

Solution

a = (-2, 2),           b = (0, -6)

a + b = (-2 +0, 2 - 6) = (-2, -4)

a – b = (-2, 8)

4a + 5b = (-8, 8) + (0, -30) = (-8, -22)

4a – 5b = (-8, 8) - (0, -30) = (-8, 38)

IaI = sqrt(4 + 4) = 2.83