A-LevelMathematicsSeries9709/12 · Feb/Mar 2021 · Q15 Marks
Find the first three terms in the expansion, in ascending powers of x, of (1 + x)5.
- (a)Find the first three terms in the expansion, in ascending powers of x, of (1 + x)5.[1]
- (b)Find the first three terms in the expansion, in ascending powers of x, of (1 – 2x)6.[2]
- (c)Hence find the coefficient of x² in the expansion of (1 + x)5(1 – 2x)6.[2]
Mark scheme
Marking points from the official mark scheme (Feb/Mar 2021). The mark or mark type is shown in brackets.
- [1] 1+5x+10x2
- [2] 1-12x+60x2 (B2 all correct, B1 for two correct components.)
- [1] (1+5x+10x2)(1-12x+60x²) leading to 60 – 60 + 10 (3 products required)
- [1] 10 (Allow 10x²)
Write your answer and get it marked
On Oracle Prep you can write or photograph your own answer and have it marked by AI against this mark scheme, with feedback on what you missed.
Sign up free →