Exercise 1 Create a method that takes a value and indicate whether it is positive or negative by a return a Boolean value. Declared as: boolean isPositive (float a) Exercise 2 Create a method that...

Extracted text: Exercise 1 Create a method that takes a value and indicate whether it is positive or negative by a return a Boolean value. Declared as: boolean isPositive (float a) Exercise 2 Create a method that takes a value and tell whether it is null or not. Declared as: boolean isZero (float a) Exercise 3 Create a method delta() that takes three values, a, b and e, which are the coefficients of a quadratic equation and returns the value of the delta, which is given by b ? - 4ac Exercise 4 Using the 3 methods above, create an application that calculates the roots of an equation of second degree: ax 2+ bx + c = 0 For it exists, the coefficient a must be nonzero, If delta is positive, then there are two distinct roots: -b+ VA and -6 - VĀ 2a 2a If delta is zero, then there is exactly one real root: 2a' If delta is negative, there is no real solution.