solve the following 9 exercises:
if senz = e ^ iz - e ^ -iz / 2i , cosz = e ^ iz - e ^ -iz / 2
1. sen^2 z + cos^2 z=1
2. 1+tan^2 z = sec^2 z
3. 1+cot^2 z = csc^2 z
4. sen(-z)=-sen z
5. cos (-z)=cos z
6. tan (-z)=-tan z
7. sen (z1+z2)=sen z1 cos z1 +sen z2 cos z2
8. cos (z1+z2)=cos z1 cos z2 - sen z1 sen z2
9. tan (z1+z2)= tan z1 + tan z2 / 1-tan z1 tan z2

Aparallel system functions whenever at least one of its components works. consider a parallel system of n components, and suppose each component works independently with probability 0.5. find the conditional probability that component n works given that the system is working

If f(x)= 3x+6 which of the following is the inverse of f(x)

You are updating your garage and the only thing left to paint is your garage day. you're only going to paint the slide that faces the street. the garage door is 9 fert 8inches tall and 120 inches wide. you need to know the surface area of the side of the garage door to determine how much paint to buy. the hardware store sells paint by how much covers a square foot. what is the surface area you should report to the hardware store what is the answer