1. Evaluate the expression Math.sqrt(1+2+3+4) 2. Evaluate the expression Math.exp(-Math.pow(Math.sin(1), 0.25)) 3. Write a Java expression to calculate the area of a triangle, given three sides a, b, c. (Heron's formula) 4. Write a Java expression for the mathematical formula. 21 5. The monthly payment cof a mortgage of n months with monthly interest rater for a principal p is given by the mathematical formula. pr(1 + r)" (1 + r)" - 1 Write a Java expression to calculate the monthly payment. 6. Lets be a string of odd length. Write a Java expression to give a substring of s with the center character removed. For example, ifs is "Program", the expression should give "Proram". 7. Lets be a string of length at least 2. Write a Java expression to give a string with the first and last characters of s swapped. For example, if sis "dog", the expression should give "god". 8. Let si and s2 be two strings of even lengths. Write a Java expression to combine the first half of si and the second half of s2, if si is "Computer" and s2 is "Programmer", the expression should give "CompProgr". 9. A string variable fullName represents a full name such as "Doe, John". Write a Java expression to give a string of first initial and last name, e.g., "). Doe". In java