Estimate the given functions.
1. j^-4
2. Represent complex number graphically and provide its polar form. -15
3. Find identity sin (alpha + beta) - sin (alpha - beta) = 2 cos lpha sin beta.
4. If tan theta = 4/8, find value of sin^2 theta + cos^2 theta?
5. Use the calculator to determine irrational root (tothe nearest 0.01) which lies between given values, r^4 - 3r^3 - r^2 - r - 5 =0 (3 and 4)