How NOT to lose marks in your LC exam

Question		How I lose marks ...		How I get them back.
Arithmetic	▼	Not giving answer in correct format.	▲	Recheck what was asked.
	▼	Not handling percentages, percentage error and taxes properly.	▲	Practice all type of percentage questions
Algebra	▼	Failing to square an expression properly (x+y)² = x² + y² + 2xy	▲	Practice
	▼	Getting sloppy towards the end of a simplification, mixing up signs, adding instead of multiplying....	▲	Practice and be careful. Then, substitute test values to verify results.
	▼	Failing to find corresponding y-values after solving for x, esp when one simultaneous equation is quadratic.	▲	Pay attention to steps of solution – always include the checking answers step.
	▼	Not handling laws of indices properly	▲	Learn these – check them on your calculator! Make sure you can enter complicated indices on your calculator correctly.
Complex numbers	▼	Failing to set i² = -1	▲	Practice.
	▼	Not recognising symbols and their meanings: complex conjugate z-bar, modulus |2+3i|	▲	Go over chapter – it is quite self-contained.
	▼	Not handling substitution properly w=2+3i, what is w²	▲	Look at past exam questions.
	▼	Not knowing quadratic formula properly	▲	Write it down and check it every day.
Functions	▼	Not showing marks on graph or understanding how to use graph,	▲	Use a pencil and ruler to show how you interpret graph.
	▼	Uneven scale on x- or y-axis	▲	Use graph paper, watch that all intervals are even, including 0 to 1, 1 to 2 etc.
Differentiation	▼	Not taking care applying rules for differentiation, or not knowing chain rule (it is not in tables)	▲	Learn it and practice.
	▼	Leaving out LHS or Limit idea in first principles.	▲	Practice.
Perimeter, area & volume	▼	Not knowing simpson's rule inside out.	▲	Practice, especially with unknown heights etc.
	▼	Not handling Π as requested.	▲	Re-check what you are asked.
	▼	General errors applying formulae.	▲	Practice using tables for formulae, and sanity check your answers.
Co-ordinate geometry of line	▼	Not knowing formulae and how to apply them.	▲	As for quadratic formula, write them out each day – make sure you understand logic of slope, midpoint and distance formulae.
	▼	Uneven scale on x- and y-axis (must be both to same scale)	▲	Use graph paper and check this.
Co-ordinate geometry of circle	▼	Not taking minus signs into account in formula for equation of circle (e.g. (x-2)² + (y+3)² = 8 means centre of circle is (2,-3) and radius = √8	▲	Practice.
	▼	Failing to understand geometry of circle (tangent at a point perpendicular to radius, tangents at opp end of diameter are parallel)	▲	Go over JC geometry if necessary.
Trigonometry	▼	Not knowing or correctly using Sin= 0pp/Hyp etc	▲	Learn mnemonic.
	▼	Failing to “fill out” the sine rule/ cosine rule correctly.	▲	Practice.
	▼	Being caught out by inverse sine of an angle that is >90º	▲	Be alert.
	▼	Having calculator set to radians or not knowing how to use degrees/minutes function.	▲	Check it and practice.
Probability	▼	Not showing your work	▲	Can be difficult, but write something in case your answer is wrong.
	▼	Failing to see that there are two ways a combined event can happen and adding probabilities of each.	▲	Use a sample space to check answers
Statistics	▼	Forgetting to divide by sum of frequencies	▲	Sanity check answers
	▼	Not showing marks on graph (eg median from ogive)	▲	Indicate how you use graph clearly
Linear programming	▼	Not indicating half-plane when graphing inequalities	▲	Include it in your graph.
	▼	Leaving out the “obvious” inequalities, x≥0	▲	Make sure you give the number of inequalities you were asked for.
	▼	Not using simultaneous equations to calculate point of intersection.	▲	You must not use your graph for this part.
	▼	Not writing english sentence at the end	▲	Explain what x=10, y=7 means, 10 what, 7 what and why (“to maximise profit” or whatever).