2 Finds 8 b) 3 Evaluates 3 #2.1 Knows to use scalar product. #2.1 strategy #2.2 Since , ABCD is not a rectangle. #2.2 Explains solution may be awarded for evaluating any •3 suitable scalar product, eg . For #2.2 do not accept statements such as ABCD is not a ‘so rectangle’. For candidates who elect to use the converse of Pythagoras’ theorem: eg and •3 #2.1 Knows to use converse of Pythagoras LHS and RHS – independently evaluated eg and . #2.2 Since , ABCD is not a rectangle by the converse of Pythagoras. Notes: Do not award #2.1 for a statement such as . #2.2 is only available if of Pythagoras’ appears. ‘converse 8 c) Uses scalar product •1 •1 127.3 or 2.22 radians (accept 127 or •2 2.2 rads) angle •2 Notes: Candidates who use the cosine rule can be awarded full credit: 9(a) 1 use 1 (b) 2
2 Finds 8 b) 3 Evaluates #2.1 strategy #2.2 Explains solution 3 #2.1 Knows to use scalar product. #2.2 Since , ABCD is not a rectangle. •3 may be awarded for evaluating any suitable scalar product, eg . For #2.2 do not accept statements such as ‘so ABCD is not a rectangle’. For candidates who elect to use the converse of Pythagoras’ theorem: •3 eg and #2.1 Knows to use converse of Pythagoras – LHS and RHS independently evaluated eg and . #2.2 Since , ABCD is not a rectangle by the converse of Pythagoras. Notes: Do not award #2.1 for a statement such as . #2.2 is only available if ‘converse of Pythagoras’ appears. 8 c) •1 Uses scalar product •2 angle •1 •2 127.3 or 2.22 radians (accept 127 or 2.2 rads) Notes: Candidates who use the cosine rule can be awarded full credit: 9(a) (b) 1 use 1 2