Use the Quadratic Formula to find the exact solutions of x2 + 7x − 4 = 0. x equals negative b plus or minus the square root of b squared minus 4 times a times c, all over 2 times a

∠acb = 8°

step-by-step explanation:

∠xba lies on the circle and is half the measure of the intercepted arc ax

hence

measure of arc ax = 2 × 42° = 84°

∠acb is outside the circle and is

∠acb = (arcab - arcax ), hence

∠acb = 0.5 (100 - 84) = 0.5 × 16° = 8°