Prove each identify
cos X(tanX+cotX) =cscX

Given the function f(x) = log base 4(x+8) , find the value of f^-1(2)

Can someone me and do the problem plz so i can understand it more better

Astuntman jumping off a 20-m-high building is modeled by the equation h=20-5t^2, where t is the same in seconds. a high-speed camera is ready to film him between 15m and 10m above the ground. for which interval of time should the camera film him?