Moderate -0.8 This is a straightforward differentiation and substitution question requiring only basic exponential differentiation (dy/dx = 6e^{2x}) and solving 3e^{2x} = 10 to find x, then substituting back. It's easier than average as it involves routine application of standard techniques with no problem-solving insight needed, though the substitution step adds minimal complexity beyond pure recall.
Question 5:
5 | Obtains 2×3e 2x or 6e 2x or 2y
PI by correct answer | 1.1b | B1 | dy
=2×3e2x
dx
dy
y =10⇒ =2×10=20
dx
Substitutesy =10or 3e 2x =10
dy
in their
dx
or
substitutes x = [0.6, 0.602] or
1 10 dy
x= ln OE in their
2 3 dx | 1.1a | M1
Obtains 20
CAO
20 cannot come from a rounded
value for 20 seen | 1.1b | A1
Question 5 Total | 3
Q | Marking instructions | AO | Marks | Typical solution