f(x)= lnx
y' = -2e^(-2x)
f(x)= e^5x
f(x)= cscx
y' =coshx
y' =5e^5x
y' = e^x
f(x)= cosx
f(x)= senhx
y' = secx.tangx
f(x)= e^-2x
y' =-cscx.cotgx
f(x)= tangx
f(x)= e^x
y' =1/x
y' = -senx
