The value of a car t t\,t years after it was purchased is modelled by the formula V=A+Be−t6\displaystyle V = A + Be^{-\frac{t}{6}}V=A+Be−6t where V V\,V is the value of the car in thousands of pounds, and A A\,A and B B\,B are constants.
The graph of V V\,V against t t\,t passes through (0,18)(0, 18)(0,18) and (6,7)(6, 7)(6,7), and the line V=kV = kV=k is an asymptote to the curve.
Find the values of AAA, B B\,B and kkk, giving your answers to 3 significant figures where appropriate.
104 exam-style questions on WJEC A Level Maths 1.6 Exponentials and logarithms, covering 1.6.1 Exponentials and logarithms, 1.6.2 Exponentials and logarithms, 1.6.3 Exponentials and logarithms, 1.6.4 Exponentials and logarithms, 1.6.5 Exponentials and logarithms, 1.6.6 Exponentials and logarithms, 1.6.7 Exponentials and logarithms, 1.6.8 Exponentials and logarithms, and 1.6.9 Exponentials and logarithms. Each one has a worked solution and a mark scheme showing where the marks go.