In Exercises 1-4, (a)use a graphing utility to grapheach side of the equation to determine whether the equation is an identity, (b)use the table feature of the graphing utility to determine whether the equation is an identity, and (c)confirm the results of parts(a) and (b) algebraically
1. (1 + cot2 x)(cos2 x) = cot2 x
2. csc x(csc x - sin x) + sin x - cos x / sin x + cot x = csc2 x
3. 2 + cos2 x − 3 cos4 x = sin2 x(3 + 2 cos2 x)
4. tan4 x + tan2 x − 3 = sec2 x(4 tan2 x − 3)