Demonstrandum/basic_ruby.rb

## basic_ruby.rb

def f x; x**2 + 2*x + 1; end

def integrate sym, a, b
  dx = 0.001
  fn = method sym
  dx * (a..b - dx).step(dx).map(&fn).sum
end

puts integrate :f, 2, 4

def differentiate sym, x
  h = 0.001
  fn = method sym
  (fn.call(x + h) - fn.call(x)) / h
end

puts differentiate :f, 7

	def f x; x*2 + 2x + 1; end

	def integrate sym, a, b
	dx = 0.001
	fn = method sym
	dx * (a..b - dx).step(dx).map(&fn).sum
	end

	puts integrate :f, 2, 4

	def differentiate sym, x
	h = 0.001
	fn = method sym
	(fn.call(x + h) - fn.call(x)) / h
	end

	puts differentiate :f, 7