Asap ! find the sine ratio of angle

What is the common difference in the following arithmetic sequence? 7,3,-1,-5

Apolynomial function has a root of –6 with multiplicity 1, a root of –2 with multiplicity 3, a root of 0 with multiplicity 2, and a root of 4 with multiplicity 3. if the function has a positive leading coefficient and is of odd degree, which statement about the graph is true?

Express the following as a function of a single angle. cos(60) cos(-20) - sin(60) sin(-20)