Presentation on theme: "Ζ GCSE- Changing the Subject Dr Frost Objectives: To be able to change the subject of a formula where the term appears multiple times, and where the equation."— Presentation transcript:
ζ GCSE- Changing the Subject Dr Frost Objectives: To be able to change the subject of a formula where the term appears multiple times, and where the equation may contain fractions and brackets.
Starter The formula to calculate a temperature in Fahrenheit if we have the temperature in Celsius: How could we find a new formula that allows us to determine the temperature in Celsius given the temperature in Fahrenheit? ?
(4 marks) A* Question What does it mean to make n the “subject of the formula”? Can we think of generic tips that will help us solve these kinds of questions?
Using your solution to the previous question... TipWhy?When? When fractions present, multiply both sides of the equation by the denominators. Allows us to collect like terms more easily. Immediately! Expand out any brackets.Allows us to collect like terms more easily. Once we we’ve eliminated fractions. Factorise out new subject. Now only one occurrence of new subject in equation. When terms involving subject all on one side of equation. Collect terms involving new subject on one side of equation. So that we can then factorise. When new subject is free from fractions and brackets. ?? ?? ?? ??
Another A* Question (Note: According to the Examiner’s Report, only 5% of students got full marks to this question) Make a the subject of the formula: Answer: ?
Challenges ? ? ?
EdExcel Mock Paper Q4 Q5 EdExcel Mar 2012: Q3 EdExcel Nov 2012: Q6 EdExcel May 2009: Q2 EdExcel Nov 2009: Q7 Q8 EdExcel Nov 2009: EdExcel Jun 2011: Q9 EdExcel Nov 2002: Questions O Level 1957: Q10 Q1 ? ? ? ? ? ? ? ? ? ?
Final tips? What tips would you give to someone answering the following questions? Make a the subject of the formula:Make x the subject of the formula: