Target Mathematics

1.49: Logarithmic equations and exponential equations

4PM1/2/June/2018 — Question 4 · 9 marks

(a) Find the exact value of the root of the equation e3x=8e^{3x}=8.
Give your answer in the form lna\ln a, where aa is an integer. (2)
The curve C1C_1 has equation y=2e3xy=2e^{3x} and the curve C2C_2 has equation y=(e3x4)2y=(e^{3x}-4)^2.
The curves C1C_1 and C2C_2 intersect at the points PP and QQ.
(b) Use algebra to find the exact coordinates of the points PP and QQ. (5)
(c) Find, to 3 decimal places, the length of PQPQ. (2)