Level 2 Calculus Walkthrough
2025 NCEA Level 2 Calculus Question 1(b)
2025 Paper — Tangent equation for a cubic
Question
Find the equation of the tangent to the curve at \(x=2\).
Start by finding the point of tangency, then differentiate to get the gradient, and finally use point-slope form.
A later walkthrough visual becomes available with JavaScript; the complete question and first learning steps remain below.
First walkthrough idea
Tip to try first
Substitute \(x=2\) into the original function first so you know the point where the tangent touches the curve.
Step 1
Find the point of tangency
Reveal the explanation and working for this step.
Show the first step’s working
Evaluate the function at \(x=2\) to locate the point of tangency.
Key result
\(f(2)=-\frac{8}{3}+8-6+6=\frac{16}{3}\), so the point of tangency is \(\left(2,\frac{16}{3}\right)\).
Walkthrough overview
What this question practises
This 2025 walkthrough is part of AS91262 — Apply calculus methods in solving problems.
Method: Finding the point of tangency, the gradient, and the tangent equation.
This is Question 1(b) from the 2025 NCEA Level 2 Calculus paper for AS91262 — Apply calculus methods in solving problems. Use the guided hints to practise the method before revealing the full working.
Calc.nz is an independent learning resource. Compare questions, diagrams, and assessment information with the official NZQA resources for AS91262.
Page updated .
Learning summary
Review the method, not only the answer
This walkthrough helps you practise finding the point of tangency, the gradient, and the tangent equation. Use the hints to plan the method, then repeat the question without hints and check each step.
Common mistake to avoid
Use the derivative for the gradient and the original curve for the point before forming the tangent equation.