Find the value of x (no labels)

[10 points, algebra 2-simplifying complex fractions]according to my answer key the restrictions are -1 and 4. but why not positive 1?

Given sin28.4=.4756, cos28.4=.8796, and tan28.4=.5407 find the cos of 61.6

The correlation coefficient between the number of students and marks obtained in end semester exam. (13 marks) give the statistical meaning of the relationship between the number of students and marks b. obtained in end semester exam. (3 marks) draw the number of students and marks obtained in end semester exam scatter diagram c. (4 marks) check list write your name and id corectly write the question number properly use your own calculator. show all the steps to solve the problems. use the correct formula. answer in provided time. don't use your mobile for any purpose. write your answer up to two decimal places