Mathematics · May / June 2021 · Paper 41 · Question 7

x + 5 final answer x + 4 [3]

B1 for ( − )( + ) x 5 x 5

B1 for ( − )( + ) x 5 x 4

2 2 2 x + 12 x − 5 2 x + 12 x − 5 or x x ( − 1 ) x 2 − x final answer [3]

B1 for common denominator ( x x − ) 1 oe

B1 for ( − )( + ) + ( + ) x 1 x 5 x x 8 or better

2 6 x − 8 x final answer [2]

B1 for each term in final answer

or M1 for correct answer seen and spoilt

64 [2]

FT their (c)(i) correctly evaluated provided at least 2 terms but not the original equation

M1 for substituting x = 4 into their (c)(i)

(0, 6) 4 98 , oe 3 27 [4]

M1 for their derivative = 0 or dy dx = 0 soi

B1 for x = 0 and x = 4 3 M1dep for substituting one of their x values 3 2 into y = 2 x − 4 x + 6 soi