Common Mistakes in Cambridge A Level Mathematics
Success in A Level Maths often comes from avoiding common errors in calculation, interpretation, and reasoning. Awareness of these pitfalls is the first step to correcting them.
Errors in Pure Mathematics
- Forgetting the constant of integration, '+ C'. Always add '+ C' immediately after performing an indefinite integration.
- Working in degrees when the question requires radians in calculus. Check your calculator mode before any trigonometry calculation, especially in calculus.
- Incorrectly applying logarithm laws, like writing log(x-y) as log(x) - log(y). Review and practice the fundamental laws of logarithms until they are second nature.
- Making sign errors when expanding brackets or rearranging equations. Write out each step of your algebraic manipulation clearly and double-check your work.
- Stating an answer without showing sufficient working. Show all logical steps, as method marks are awarded even if the final answer is wrong.
- Misreading inequalities, especially when multiplying or dividing by a negative number. Remember to reverse the inequality sign when multiplying or dividing by a negative.
Errors in Mechanics and Statistics
- Using g = 10 or g = 9.81 instead of the required g = 9.8 in Mechanics. Always use the value of g specified on the exam paper's cover sheet.
- Confusing permutations (order matters) and combinations (order does not). Ask yourself if arranging the items differently creates a new outcome.
- Forgetting to apply continuity corrections for normal approximations. When approximating a discrete distribution with a continuous one, adjust the value by ±0.5.
- Mixing up displacement, velocity, and acceleration. Differentiate displacement for velocity, and velocity for acceleration. Integrate in reverse.