LET’S TRY ONE
Find the limit of 2x2 + (3)x + (1) as x approaches 2.
15
Polynomials are continuous. Substitute x=2: 2(2)2 + (3)(2) + (1) = 15.
Learning steps & teaching tips
Use continuity to evaluate a polynomial limit by substitution.
- Check that the expression is a polynomial, then substitute carefully with parentheses.
- Work through the example and explain why each operation is used.
- Estimate or use another method to check the result before choosing.
Try it together
Work with a partner: solve one example, explain the method, then change one number and predict what changes.
Check that the expression is a polynomial, then substitute carefully with parentheses.