3 deleted 1 character in body
source | link

Scala, 67 6362 bytes

def e(a:(Int, Int)*)=math.sqrt(a map(x=>x._2-x._1)map(x=>x*x)sum)

Requires input as a sequence/vector of var-arg tuples
Example:

scala> e((1, 5), (2, 6), (3, 7), (4, 8))
res1: Double = 8.0

Scala, 67 63 bytes

def e(a:(Int, Int)*)=math.sqrt(a map(x=>x._2-x._1)map(x=>x*x)sum)

Requires input as a sequence/vector of var-arg tuples
Example:

scala> e((1, 5), (2, 6), (3, 7), (4, 8))
res1: Double = 8.0

Scala, 67 62 bytes

def e(a:(Int,Int)*)=math.sqrt(a map(x=>x._2-x._1)map(x=>x*x)sum)

Requires input as a sequence/vector of var-arg tuples
Example:

scala> e((1, 5), (2, 6), (3, 7), (4, 8))
res1: Double = 8.0
2 added 38 characters in body
source | link

Scala, 6767 63 bytes

def e(a:Seq[(Int, Int)]*)=math.sqrt(a map(x=>x._2-x._1)map(x=>x*x)sum)

Requires input as a sequence/vector ofsequence/vector of var-arg tuples 
Example:

scala> e(Seq((1, 5), (2, 6), (3, 7), (4, 8)))
res1: Double = 8.0

Scala, 67 bytes

def e(a:Seq[(Int, Int)])=math.sqrt(a map(x=>x._2-x._1)map(x=>x*x)sum)

Requires input as a sequence/vector of tuples Example:

scala> e(Seq((1, 5), (2, 6), (3, 7), (4, 8)))
res1: Double = 8.0

Scala, 67 63 bytes

def e(a:(Int, Int)*)=math.sqrt(a map(x=>x._2-x._1)map(x=>x*x)sum)

Requires input as a sequence/vector of var-arg tuples 
Example:

scala> e((1, 5), (2, 6), (3, 7), (4, 8))
res1: Double = 8.0
1
source | link

Scala, 67 bytes

def e(a:Seq[(Int, Int)])=math.sqrt(a map(x=>x._2-x._1)map(x=>x*x)sum)

Requires input as a sequence/vector of tuples Example:

scala> e(Seq((1, 5), (2, 6), (3, 7), (4, 8)))
res1: Double = 8.0