String 'Regex' Validation for below scenario

var variables = ['A','B'];
var allowedMathFunc = ['Sin','Cos','Tan']
var expression= 'Sin(B)+Tan(B)+100+acos(A)+C'

I want to validate expression string match below scenario

1. expression should use variables array values
2. expression should not contain other then allowed math functions.

I tried below code

var variables = ['A','B'];
var allowedMathFunc = ['Sin','Cos','Tan']
var expression= 'Sin(B)+Tan(B)+100+acos(A)'

for variable check I tried this 
let expressionVariables = value.replace(/Sin|Log|Exp|Tan|Pos|Rnd|[^A-Za-z]/ig,"");
let expressionUnUsedVar= variables.filter(v=> !expressionVariables.includes(v));

I don't know how to write for both scenario for regex it's not a problem for two different regex.

You can use regex to extract all variables and function names, and then check them if they're included in the allowed function and variable lists (case sensitive):

function testExpression(expression, vars, funcs) {
  const usedVariables = expression.match(/\b[a-z]+\b(?!\s*\()/gi) || [];
  const usedFunctions = expression.match(/\b[a-z]+\b(?=\s*\()/gi) || [];
  return usedVariables.every(v => vars.includes(v)) && usedFunctions.every(func => funcs.includes(func));
}

var variables = ['A','B'];
var allowedMathFunc = ['Sin','Cos','Tan']
var expression= 'Sin(B)+Tan(B)+100+acos(A)+C'
console.log(testExpression(expression, variables, allowedMathFunc));

console.log(testExpression('Sin(B)+Tan(B)+100+Cos(A)+C', ['A','B','C'], ['Sin','Cos','Tan']));