Which equation has real, rational, and unequal roots?
1) r^2+ 10x + 25 = 0
2) r^2 - 5x + 4 = 0
3) r^2 - 3x + 1 = 0
4) r^2 - 2x + 5 = 0

Afactory makes propeller drive shafts for ships. a quality assurance engineer at the factory needs to estimate the true mean length of the shafts. she randomly selects four drive shafts made at the factory, measures their lengths, and finds their sample mean to be 1000 mm. the lengths are known to follow a normal distribution whose standard deviation is 2 mm. calculate a 95% confidence interval for the true mean length of the shafts. input your answers for the margin of error, lower bound, and upper bound.

The distance of a chord from the centre of a circle is 12cm and the lenght of the chord is 10cm. find the radius of the circle

Solve for x and select the correct answer