#1
eks = function(x,lambda){lambda*exp((-1)*lambda*x)}
eks(4,0.06)

## [1] 0.04719767

#untuk P(X=15)
cdfexp = function(x,lambda=0.06){
  pdf = function(t){
    lambda*exp(-lambda*t)
  }
  hasil = integrate(pdf,lower=0,upper=x)
  return(hasil$value)
}
cdfexp(4,0.06)

## [1] 0.2133721

#2
uniform <- function(x,a=0,b=1) {1/(b-a)}
uniform(6, a = 2 , b =10)

## [1] 0.125

dunif(6,min=2,max = 10)

## [1] 0.125

#3
norm = function(x,miu,sigma){1/(sigma*sqrt(2*pi))*exp(-1/2*((x-miu)/sigma)^2)}
norm(4,5,1)

## [1] 0.2419707

dnorm(4,mean=5,sd=1)

## [1] 0.2419707